Polymers I - SchoolWorld an Edline Solution我schoolworld艾里尼溶液的聚合物
Confined Polymers Big World in a Small Space密闭的聚合物大世界在一个小空间共33页
* in the test tube
* in polymer brushes
* in mesoscopic channels
Adrian Parsegian and many friends: Sergey Bezrukov, Joel Cohen, Per Lyngs Hansen,
M a c in to s h P IC T im a g e fo rm a t
is n o t s u p p o rte d
~ 1, crudely speaking
cp = molar concentration Cp = weight concentration Mm = monomer weight
5 10 15 20 25 30
PEG 3400, weight %
MW 3400 ~ 77 monomers of length 3.4 Angstroms Stretches to ~ 28 nm (vs. ~10 nm length of pore) Rg ~ 2.5 nm in dilute solution ( vs. ~ 1 nm radius of pore)
Test tube
~cm
vs.
~nm
grafted,
between bilayers
vs. inside a pore
~10 nm ~nm
Schematic of force measurement between PEG lipids
~ cm
Posmotic
Equilibrate in high-concentration 9/4-power limit
POLYMERS - Free website Free blog Create a free website 聚合物的免费网站免费博客创建一个免费的网站
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Limitations of Polymers
▪ Low strength relative to metals and ceramics ▪ Low modulus of elasticity (stiffness) ▪ Service temperatures are limited to only a few
▪ Symbolized by TS
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Elastomers (Rubbers)
Polymers that exhibit extreme elastic extensibility when subjected to relatively low mechanical stress
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e
Polymer
A compound consisting of long-chain molecules, each molecule made up of repeating units connected together
《聚合物流变学》课程教学大纲(本科)
聚合物流变学(Rheology for Polymer)课程编号：07410156学分：2学时：32 （讲课学时：32）先修课程：高等数学，大学物理，高分子物理适用专业：高分子材料与工程教材：高分子流变学基础，史铁钧、吴德峰著.北京：化学工业出版社，2011年4 月第一版一、课程的性质与任务：（-）课程性质（需说明课程对人才培养方面的贡献）本课程是面向高分子材料与工程高年级本科生的专业基础选修课，本课程的内容与高分子成型加工、高分子工程、高分子物理等方向密切相关，是高分子材料专业学生进一步开展这些方向的深入学习和研究的基础。
本课程旨在介绍聚合物熔体流变学原理及其在加工过程中的专业应用，通过研究热和力对聚合物流体流动和变形的影响。
使学生了解聚合物熔体的粘性流动、弹性效应及其流变测定法、守恒方程和本构方程、流体在简单几何形状流道中的流动，以及挤出、注塑、压延和吹塑等成型过程中的流动。
另外，对挤出机、双辐机和密炼机的混合特性进行研究，使学生进一步掌握各种高分子材料成型工艺。
本课程的主要目的是使学生掌握相关流变学的思想，理解相关理论，并能够利用流变学相关理论知识解决工程中遇到的实际问题。
（二）课程目标（根据课程特点和对毕业要求的贡献，确定课程目标。
应包括知识目标和能力目标。
）课程目标1:掌握聚合物材料的独特流变学特征，并理解相关机理；课程目标2：掌握聚合物结构与其流变学特征之间的关系；课程目标3：掌握流变学性能的相关测试及其原理；课程目标4：掌握影响聚合物流变学特征的各种因素，能够通过调控相关因素来控制流变行为。
二、课程内容与教学要求（按章撰写）第一章绪论（一）课程内容（列出主要知识点、能力点）（1）流变学的历史和现状（2）流变学的研究对象和方法（3）高分子材料典型的流变行为（4）流变学在高分子材料加工中的应用（二）教学要求（将相关内容按照掌握、理解、了解等不同教学要求进行分类）通过学习使学生掌握聚合物流变学的基本概念、内容和意义，了解聚合物流变学的发展历史，懂得聚合物流变学的发展趋势和方向，了解聚合物流变学中的一些奇特现象以及理解产生这种特殊的行为的物理原因是什么。
“高分子流变学”外文原版教材现状
ｐｅ ｌｉｓ ｌ Ｆｕｄ 介绍 了复杂流体 的流 变特性 ｘ 和结构 之 间的关 系 。Ａ ｎｒｄ ｃｉ ｏ ｎ Ｉｔ ｕｔｎ ｔ ｏ ｏ Ｒ ｅｌ ｙ 绍 了流 变学及其 在产 品加工 ｈｏｏ 介 ｇ
、
国外流变学教材 现状
Ｒ ｅｌ ｙ 盖 了理解 粘弹性 所必须 的背 ｈｏ ｇ 涵 ｏ 景知识 ，讨论 了粘 弹性材料 的连续统模
型 和 微 观 模 型 。 Ｐ ｌ ｒ Ｖｓｏｌ ｔｉ ： ｏ ｍｅ ｉ ｅ ｉ ｔ ｙ ｃ ａ ｃｙ ｓ
在 引进 原版教材时 涉及 版权 问题 ，其版 权 费相 当高 。这会加重学生 的经济负担 。 最后 ，语言难度不 能与我国学生 的实 际 英语水 平吻合 ，编写思 维方式与我 国存 在差异 ， 不符合 中国人 的阅读习惯 ， 学生
数学的使用 。 ｈｏ ｇ ｕｄｍ ｎ ｌ通俗 Ｒ ｅｌ ｙＦｎａ ｅｔｓ ｏ ａ
地讲述 了流变学 的基本原理 。 （） ２ 高分子 流变 学 的某一 个领 域 的 著作 ｏＳｒｃ ｒ ｎ ｈｏ ｇ ｆＭｏｔ ｔ ｔ ｅ ａｄ Ｒ ｅｌ ｙ ｏ ｌ ｎ ｕｕ ｏ ｅ
流变学双语教材建设 。
双语 教学是 非外语专业 使用外语和
汉 语讲 授 书 本专 业 知识 的一 种教 学 方
Ｐｌｍ ｒ 介绍 了高分 子流变 行为 和高分 ｏ ｅｓ ｙ 子熔 体 结 构 之 间 的关 系 。 Ｎ ｎ ｒｅｌ ｙ ａｏｈｏｏ ｇ
ｏ ｔ ｎ ｌ ｏ ｇ ｅ ｌ ｃ ｌｒ ｆｕｄ ：ａ ｆ ｓｒ ｇｙ ｃ ｎ ｎ ｄ ｍｏ ｅ ｕａ ｉ ｓ ｏ ｌ
ｓ ｎ ｐ ｌ ａ ｏｓ简化 了符 号 ， ，ａ ｄＡ ｐｉ ｔｎ ｃｉ 克服 了
IntroductiontoPolymer聚合体简介课件
IntroductiontoPolymer聚合体简介
9
聚苯乙烯 Polystyrene
比重:1.05克/立方厘米 成型收缩率:0.6-0.8% 成型温度： 170-250℃
特点：电绝缘性(尤其高频绝缘性)优良,无色透明,透光率仅次于 有机玻璃,着色性耐水性,化学稳定性良好,.强度一般,但质脆,易 产生应力脆裂,不耐苯.汽油等有机溶剂.
成型特性： 1.结晶料,吸湿小,不须充分干燥,流动性极好流动性对压力敏感,成型时 宜用高压注射,料温均匀,填充速度快,保压充分.不宜用直接浇口,以防收 缩不均,内应力增大.注意选择浇口位置,防止产生缩孔和变形. 2.收缩范围和收缩值大,方向性明显,易变形翘曲.冷却速度宜慢,模具设 冷料穴,并有冷却系统. 3.加热时间不宜过长,否则会发生分解. 4.软质塑件有较浅的侧凹槽时,可强行脱模. 5.可能发生融体破裂,不宜与有机溶剂接触,以防开裂.
IntroductiontoPolymer聚合体简介
4
塑胶的分类 3
按加工方法分类
膜压塑料多为物性的加工性能与一般固性塑料相类似 的塑料；
层压塑料是指浸有树脂的纤维织物，经叠合、热压而 结合成为整体的材料；
注射、挤出和吹塑多为物性和加工性能与一般热塑性 塑料相类似的塑料；
浇铸塑料是指能在无压或稍加压力的情况下，倾注于 模具中能硬化成一定形状制品的液态树脂混合料，如 MC尼龙等；
材料 聚苯乙烯
密度/(g/cm3) 1.41～1.43
聚苯醚
1.47～1.52
苯乙烯-丙烯腈共聚物
1.47～1.55
尼龙610
1.50～2.00
尼龙6
1.70～1.80
尼龙66
1.80～2.30
高分子化学中英文对照
新序码汉文名05.高分子化学05.1高分子物质英文名注释咼分子macromolecule, polymer 超高分子supra polymer天然高分子n atural polymer无机高分子inorganic polymer有机高分子orga nic polymer无机-有机高分子inorganic orga nic polymer 金属有机聚合物orga no metallic polymer 兀素咼分子eleme nt polymer咼聚物high polymer聚合物polymer低聚物oligomer二聚体dimer三聚体trimer调聚物telomer预聚物prepolymer均聚物homopolymer无规聚合物ran dom polymer无规卷曲聚合物ran dom coili ng polymer 头-头聚合物head-to-head polymer头-尾聚合物head-to-tail polymer尾-尾聚合物tail-to-tail polymer反式有规聚合物tran stactic polymer顺式有规聚合物cistactic polymer规整聚合物regular polymer非规整聚合物irregular polymer 又称大分子曾用名齐聚物1 2 3 4 5 6 7 8 91011121314151617181920212223242526 无规立构聚合物atactic polymer27 全同立构聚合物isotactic polymer 又称等规聚合物”。
28 间同立构聚合物syn diotactic polymer 又称间规聚合物”。
29 杂同立构聚合物heterotactic polymer 又称异规聚合物”。
30 有规立构聚合物stereoregular polymer, tactic polymer 又称有规聚合物”。
31 苏型双全同立构聚合物threo-diisotactic polymer32 苏型双间同立构聚合物threo-dis yn diotactic polymer33 赤型双全同立构聚合物erythro-diisotactic polymer34 赤型双间同立构聚合物erythro-dis yn diotactic polymer35 全冋间冋等量聚合物equitactic polymer36 共聚物copolymer37 二兀共聚物binary copolymer38 三兀共聚物terpolymer39 多元聚合物multipolymer40 序列共聚物seque ntial copolymer41 多层共聚物multilayer copolymer42 多相聚合物multiphase polymer43 统计［结构］共聚物statistical copolymer44 无规共聚物ran dom copolymer45 父替共聚物alter nat ing copolymer46 周期共聚物periodic copolymer47 梯度共聚物gradie nt copolymer48 嵌段共聚物block copolymer 又称“嵌段聚合物(blockpolymer) ”。
高分子材料专业课程中英文名称与简介
生产实习（Advanced Practicum）本课程是材料科学与工程本科专业的必修课。
课程内容包括带生到工厂和科研院所了解和实践专业知识在实际生产中的应用。
同时配合仿真实习软件掌握化工生产工艺的操作，为学生进社会工作打好基础。
材料学院开课；预修：PSE3840T，PSE3620T。
橡胶工程高等实验（Rubber Engineering Advanced Experiment）本课程开设研制弹性体高分子材料的综合实验，以完成小型科题的训练为教学目标，培养学生的基本科研素质和创新能力。
教师给出科研课题，学生自行设计方案，完成材料选用、配合点、测试表征方案、结果与讨论等步骤。
最后撰写实验和研究报告。
材料学院开课；预修：PSE3620T，PSE3840PSE3421T。
文献查阅（Literature Searching）本课程的特点：是一门实践课；掌握文献检索的基本知识；工具书的使用方法；熟悉图书馆的检索方法；记住必要的专业术语；掌握相关检索工具的网络检索方法。
材料学院秋季开课预修：MSE2022T，MSE2140T，MSE3440T。
聚合物表征（Techniques for Characterization of Polymers）本课程是材料学专业的核心基础课程系统讲授聚合物结构与性能表征的分析方法，主要内容包括：波谱分析，聚合物分子质量及分子质量分布表征，聚合物微结构分析，聚合物热分析，聚合物流变性能分析，聚合物动态力学分析。
材料学院秋季开课；预修：PSE2150PSE2250T，PSE3620T。
橡胶制品及模具设计（Rubber Products and Mold Design）介绍国内外橡胶工业制品种类及生产，讲述橡胶模压制品设计一般要求和规律，讲述橡胶压模类型对制品的影响、结构设计、模具导向与定位、模具的尺寸与强关系、模具材料、热处理及表面处理的要求及模具的尺寸公差与配合、整体设计。
材料学院秋季开课；预修：M1120T，MEE2250T，MEE1640T。
高分子材料与工程英语自我介绍
高分子材料与工程英语自我介绍English:I am a passionate and dedicated individual with a strong background in polymer materials and engineering. My education and experience have equipped me with a deep understanding of the principles and applications of various polymer materials, such as thermoplastics, thermosets, elastomers, and composites. I have hands-on experience in polymer processing techniques, such as injection molding, extrusion, and blow molding, and I am proficient in using software tools for polymer analysis and simulation. In addition, I have worked on research projects related to polymer synthesis, characterization, and modification, which have allowed me to develop critical thinking and problem-solving skills in this field. I am enthusiastic about applying my knowledge and skills in high-performance polymer materials to contribute to innovative solutions in industries such as automotive, aerospace, and electronics.中文翻译:我是一名热情且专注的个体，在高分子材料与工程领域拥有扎实的背景。
高分子世界PolymerWorld-高分子科学与工程系
PU 或 PVC
Angew. Chem. Int. Ed., 2013，52，9422-9441.
三、发展历程
天然高分子利用
7000多年前，天然油漆 我国已使用天然油漆涂饰船只。中国漆(大漆)
1839年，天然橡胶硫化 美国人古德伊尔（Charlers Goodyear）。 1869年，第一种人工塑料 赛璐珞（ Celluloid，硝化纤维素） 美国 人海厄特（Jhon Wesley Hyatt）。 1887年，第一种人造丝 硝化纤维素，Count Hilaire de Chardonnet.
纤 维 Fibers
天然纤维：棉、麻、丝 人造纤维：粘胶纤维 (Viscose fiber)：
醋酸纤维 (Acetate fiber) 硝酸纤维
合成纤维：尼龙（Nylon）：结实耐磨
涤纶（Polyester fiber）:最挺括纤维 腈纶：最耐晒的纤维 氯纶：保暖性最好的纤维 丙纶：最轻的纤维
后起之秀，生气勃勃
高分子材料
材料与时代
石器时代 (Stone age) 新石器时代 (Neolithic age) 青铜时代 (Bronze age) 铁器时代 (Iron age) 高分子时代 (Polymer age)
地位与关联
陶瓷 10％
高分子材料 60％
金属 30％
高分子科学Nobel奖获得者
P.J.Flory（美)
1974 化学奖
利用等活性假设及直接的统计方法，他计算了高 分子分子量分布，即最可几分布，并利用动力学 实验证实了等活性假设； 引入链转移概念，将聚合物统计理论用于非线性 分子，产生了凝胶理论； Flory-Huggins格子理论； 1948年作出了最重要的贡献，即提出“排除体积” 理论和θ温度概念； 他的著作“Principles of polymer chemistry” （1953）是高分子学科中的Bible。
高分子英语课文翻译
unit1all polymers are built up from bonding together a single kind of repeating unit. At the other extreme ,protein molecules are polyamides in which n amino acide repeat units are bonded together. Although we might still call n the degree of polymerization in this case, it is less usefull,since an amino acid unit might be any one of some 20-odd molecules that are found in proteins. In this case the molecular weight itself,rather than the degree of the polymerization ,is generally used to describe the molecule. When the actual content of individual amino acids is known,it is their sequence that is of special interest to biochemists and molecular biologists.并不是所有的聚合物都是由一个重复单元链接在一起而形成的;在另一个极端的情形中,蛋白质分子是由n个氨基酸重复单元链接在一起形成的聚酰胺;尽管在这个例子中,我们也许仍然把n称为聚合度,但是没有意义,因为一个氨基酸单元也许是在蛋白质中找到的20多个分子中的任意一个;在这种情况下,一般是分子量本身而不是聚合度被用来描述这个分子;当知道了特定的氨基酸分子的实际含量,它们的序列正是生物化学家和分子生物学家特别感兴趣的地方;1,题目：Another striking ...答案：.that quantity low saturation bottom much absorb 2. 乙烯分子带有一个双键,为一种烯烃,它可以通过连锁聚合大量地制造聚乙烯,目前,聚乙烯已经广泛应用于许多技术领域和人们的日常生活中,成为一种不可缺少的材料;Ethylene molecule with a double bond, as a kind of olefins, it can make chain polymerization polyethylene, at present, polyethylene has been widely used in many fields of technology and People's Daily life, become a kind of indispensable materials.Unit31 The polymerization rate may be experimentally followed by measuring the changes in any of several properties of the system such as density,refractive index,viscosity, or light absorption. Density measurements are among the most accurate and sensitive of the techniques. The density increases by 20-25 percent on polymerization for many monomers. In actual practice the volume of the polymerizing system is measured by carrying out the reaction in a dilatometer. This is specially constructed vessel with a capillary tube which allows a highly accurate measurement of small volume changes. It is not uncommon to be able to detect a few hundredths of a percent polymerization by the dilatometer technique. 聚合速率在实验上可以通过测定体系的任一性质的变化而确定,如密度、折射率、黏度、或者吸光性能;密度的测量是这些技术中最准确最敏感的;对许多单体的聚合来说,密度增加了20%-25%;在实际操作中,聚合体系的体积是通过在膨胀计中进行反应测定的;它被专门设计构造了毛细导管,在里面可以对微小体积变化进行高精确度测量;通过膨胀计技术探测聚合过程中万分之几的变化是很常见的;Unti42 合成聚合物在各个领域中起着与日俱增的重要作用,聚合物通常是由单体通过加成聚合与缩合聚合制成的;就世界上的消耗量而论,聚烯烃和乙烯基聚合物居领先地位,聚乙烯、聚丙烯等属聚烯烃,而聚氯乙烯、聚苯乙烯等则为乙烯基聚合物;聚合物可广泛地用作塑料、橡胶、纤维、涂料、粘合剂等The synthetic polymers play an increasingly important role on a range of domains, which are synthesized by monomers through addition polymerization or condensation polymerization. Polyolefin and vinyl polymer have taken the lead in terms of the world consumption. PE, PP, etc. belong to the polyolefin, while PS, PVC etc. belong to the vinyl polymer. Polymers can be widely applied in plastics, rubbers, fibers, coatings, glues and so on.Unit7Ring-opening polymerizations proceed only by ionic mechanisms, the polymerization of cyclic ethers mainly by cationic mechanisms, and the polymerization of lactones andlactones by either a cationic or anionic mechanism. Important initiators for cyclic ethers and lactone polymerization are those derived from aluminum alkyl and zinc alkyl/water systems. It should be pointed out that substitution near the reactive group of the monomer is essential for the individual mechanism that operates effectively in specific cases; for example, epoxides polymerize readily with cationic and anionic initiators, while fluorocarbon epoxides polymerize exclusively by anionic mechanisms.开环聚合反应只能通过离子机理进行,环醚的开环聚合主要通过阳离子机理,而内酯和内酰胺的聚合物是通过阳离子或阴离子机理;对于环醚和内酯型聚合物很重要的引发剂是那些来自于烷基铝和烷基锌/水的体系;应该指出的是对于在活性基团附近有取代的单体,只能由单一机理,这一机理是在特定条件下的有效;1 Polymers can be classified into two main groups, addition polymers and ___condensation__ polymers. This classification is based on whether or not the repeating unit of the polymer contains the same atoms __as____ the monomer. The repeating unit of an addition polymer is identical _with/to____ the monomer, while condensation polymers contain __different/less___ because of formation of __compound/byproduct___ during the polymerization process. The corresponding polymerization processed would then be called addition polymerization and condensation polymerization. As was mentioned earlier, this classification can result ___in__ confusion, since it has been shown in later years that many important types of polymers can be _prepared by both addition and condensation processes. For example, polyesters, polyamides and polyurethanes are usually considered to be _condensation____ polymers, but they can be prepared by addition as well as by condensation reaction. Similarly, polyethylene normally considered an _addition_ polymer, can also be prepared by _condensation_ reaction.2. Answer the following questions in English1 What is chain polymerization Manyolefinicandvinylunsaturatedcompoundsareabletoformchain-likemacromoleculesthrougheliminationofdoublebond.2 Which kinds of monomers can carry out step-growth polymerization processThere are two kinds of monomers could carry out step-growth polymerization process. One ispolyfunctionalmonomers and the other isasinglemonomercontainingbothtypesoffunctional groups.3 What properties of polymers can be based on for measuring the molecular weightThe molecular weight of polymer could be measured based on colligativeproperties, lightscattering, viscosity, ultracentrifugation sedimentation.3. Please write out at least 10 kinds of polymers both in English and in Chinesethe corresponging chemical structure5 In general,head-to-tail addition is considered to be the predominant mode of propagation in all polymerizations;However,when the substitutes on the monomer are small and do not offer appreciable steric hindrance to the approaching radical or do not have a large resonance stabilizing effect,as in the case of fluorine atoms,sizable amounts of head-to-head propagation may occur. The effect of increasing polymerization temperature is to increase the amount of head-to-head placement;Increased temperature leads to less selective more random propagation but the effect is not large. Thus,the head-to-head content in poly vinyl acetate only increases from to percent when the polymerization temperature in increased from 30 to 90 ℃.通常在所有聚合物的链增长中,头-尾加成是主要方式;然而,当单体中的取代基很小对接近的自由基没有空间阻碍或没有较大的共振稳定作用,如氟原子,则有相当量的头头增长发生;提高聚合温度的影响是提高头-头排列的量;温度的提高导致较少的选择更多的无规增长,但影响不大;因而,在聚乙酸乙烯酯中,当聚合温度由30C提高到90C,头-头含量仅由%提高到%;2．Write out an abstract in English for the text in this unitPolymers with different structures present various properties. Usually, polymers are divided into three categories, . plastic, elastomer, fiber with different initial modulus range respectively. Polymers show quite different behaviors due to the different interchain forces in elastomer and fiber. However, with the advent of new techniques and mechanisms to improve the structure of polymers, polymers may be classified and named according to the mechanism, and their properties will largely depend on the structure. 3．Put the following words into Chineseentanglement 纠缠 irregularity 无规 sodium isopropylate异丙醇钠 permeability渗透性crystallite 微晶stoichiomertric balance 当量平衡fractionation分馏法light scattering光散射 matrix 基体 diffraction衍射4．Put the following words into English形态 morphology 酯化 esterification 异氰酸酯isocyanate杂质impurity 二元胺 diamine 转化率change ratio 多分散性polydispersity 力学性能mechanical property 构象conformation 红外光谱法infrared spectroscopy常见聚合物命名1常见杂链和元素有机聚合物类型Polyamide ----聚酰胺. Polyester----聚酯 Poly‘urethane ------聚氨酯 Polysiloxane -------聚硅氧烷Phenol-formaldehyde----酚醛.Urea-formaldehyde-----脲醛Polyureas------聚脲 Polysulfide -----聚硫Polyacetal-------聚缩醛 Polysulfone polysulphone------聚砜 Polyether---------聚醚第五单元Traditional methods of living polymerization are based on ionic, coordination or group transfer mechanisms.活性聚合的传统方法是基于离子,配位或基团转移机理;Ideally, the mechanism of living polymerization involves only initiation and propagation steps.理论上活性聚合的机理只包括引发和增长反应步骤;All chains are initiated at the commencement of polymerization and propagation continues until all monomer is consumed.在聚合反应初期所有的链都被引发,然后增长反应继续下去直到所有的单体都被消耗殆尽;A type of novel techniques for living polymerization, known as living possibly use “controlled” or “mediated” radical polymerization, is developed recently. 最近开发了一种叫做活性自由基聚合的活性聚合新技术;The first demonstration of living radical polymerization and the current definition of the processes can be attributed to Szwarc.第一个活性自由基聚合的证实及目前对这一过程的解释或定义,应该归功于Szwarc;Up to now, several living radical polymerization processes, including atom transfer radical polymerization ATRP, reversible addition-fragmentation chain transfer polymerization RAFT, nitroxide-mediated polymerization NMP, etc., have been reported one after another.到目前为止,一些活性自由基聚合过程,包括原子转移自由基聚合,可逆加成-断裂链转移聚合,硝基氧介导聚合等聚合过程一个接一个被报道;The mechanism of living radical polymerization is quite different not only from that of common radical polymerization but also from that of traditional living polymerization. 活性自由基聚合的机理不仅完全不同于普通自由基聚合机理,也不同于传统的活性聚合机理;It relies on the introduction of a reagent that undergoes reversible termination with the propagating radicals thereby converting them to a following dormant form：活性自由基聚合依赖于向体系中引入一种可以和增长自由基进行可逆终止的试剂,形成休眠种：The specificity in the reversible initiation-termination step is of critical importance in achieving living characteristics.这种特殊的可逆引发-终止反应对于获得分子链活性来说具有决定性的重要意义;This enables the active species concentration to be controlled and thus allows such a condition to be chosen that all chains are able to grow at a similar rate if not simultaneously throughout the polymrization.可逆引发终止使活性中心的浓度能够得以控制;这样就可以来选择适宜的反应条件,使得在整个聚合反应过程中只要没有平行反应所有的分子链都能够以相同的速度增长;This has, in turn, enabled the synthesis of polymers with controlled composition, architecture and molecular weight distribution.这样就可以合成具有可控组成,结构和分子量分布的聚合物;They also provide routes to narrow dispersity end-functional polymers, to high purity block copolymers, and to stars and other more complex architecture.这些还可以提供获得狭窄分布末端功能化聚合物,高纯嵌段共聚物,星型及更复杂结构高分子的合成方法;The first step towards living radical polymerization was taken by Ostu and his colleagues in 1982.活性自由基聚合是Ostu和他的同事于1982年率先开展的;In 1985, this was taken one step further with the development by Solomon et al. of nitroxide-mediated polymerization NMP.1985年,Solomon等对氮氧化物稳定自由基聚合的研究使活性自由基聚合进一步发展;This work was first reported in the patent literature and in conference papers but was not widely recognized until 1993 when Georges et al. applied the method in the synthesis of narrow polydispersity polystyrene.这种方法首先在专利文献和会议论文中报道,但是直到1993年Georges等把这种方法应用在窄分子量分布聚苯乙烯之后,才得以广泛认知;The scope of NMP has been greatly expended and new, more versatile, methods have appeared. NMP的领域已经得到很大的延展,出现了新的更多样化的方法;The most notable methods are atom transfer radical polymerization ATRP and polymerization with reversible addition fragmentation RAFT.最引人注目的方法是原子转移自由基聚合和可逆加成断裂聚合;到2000年,这个领域的论文已经占所有自由基聚合领域论文的三分之一;如图所示;Naturally, the rapid growth of the number of the papers in the field since 1995 ought to be almost totally attributable to development in this area. 、自然地,纸的数量的迅速增长在领域,因为1995在这个区域应该是几乎完全可归属的到发展;UNIT9 Structure and Properties of Polymers 聚合物的结构和性质Most conveniently, polymers are generally subdivided in three categories, namelyviz., plastics, rubbers and fibers. 很方便地,聚合物一般细分为三种类型,就是塑料,橡胶和纤维; In terms of initial elastic modules, rubbers ranging generally between 106 to 107dynes/cm2, represent the lower end of the scale, while fibers with high initial modjulai, of 1010 to 1011dynes/cm2 are situated on the upper end of the scale; plastics, having generally an initial elastic modulus of 108 to 109dynes/cm2, lie in-between. 就初始弹性模量而言,橡胶一般在 6到107达因平方厘米,在尺度的低端, 10到1011达因平方厘米,尺度的高端,而纤维具有高的初始模量, 达到10到1011达因平方厘米,尺度的高端,塑料的弹性模量一般在 8到109达因平方厘米,在尺度的中间As is found in all phases of polymer chemistry, there are many exceptions to this categorization. 正如高分子化学的各个部分都可以看到的那样,在高分子化学的所有阶段,我们都可以发现,这种分类方法有许多例外的情况;An elastomer or rubber results from a polymer having relatively weak interchain forces and high molecular weights. 弹性体是具有相对弱的链之间作用力和高分子量的聚合物; When the molecular chains are “straightened out” or stretched by a process of extension, they do not have sufficient attraction for each other to maintain the oriented state and will retract once the force is released. This is the basis of elastic behavior. 当通过一个拉伸过程将分子链拉直的时候,分子链彼此之间没有足够的相互吸引力来保持其取向状态,作用力一旦解除,将发生收缩;这是弹性行为的基础;However, if the interchain forces are very great, a polymer will make a good fiber. 然而,如果分子链之间的力非常大,聚合物可以用做纤维;Therefore, when the polymer is highly stretched, the oriented chain will come under the influence of the powerful attractive forces and will “crystallize” permanently in a more or less oriented matrix. 因此,当聚合物被高度拉直的时候,取向分子链在不同程度取向的母体中将受强引力的影响而“永久地结晶;These crystallization forces will then act virtually as crosslinks, resulting in a material of high tensile strength and high initial modulus, ., a fiber. 而后,这些结晶力实际上以交联方式作用,产生高拉伸强度和高初始模量的材料,如纤维;Therefore, a potential fiber polymer will not become a fiber unless subjected to a “drawing” process, ., a process resulting in a high degree of intermolecular orientation. 因此,一个可能的潜在的纤维高分子不会变成纤维,除非经历一个拉伸过程, 即, 这导致分子间高度取向的拉伸过程;Crosslinked species are found in all three categories and the process of crosslinking may change the cited characteristics of the categories. 交联的种类在所有三种类型塑料,橡胶,纤维中找到,而交联过程可以改变分类的引用特征;Thus, plastics are known to possesspzes a marked range of deformability in the order of 100 to 200%; they do not exhibit this property when crosslinked, however. 因此,我们熟知塑料具有的形变能力大约在100-200%范围内,然而当交联发生时塑料不能展示这个性能; Rubber, on vulcanization, changes its properties from low modulus, low tensile strength, low hardness, and high elongation to high modulus, high tensile strength, high hardness, and low elongation. 对橡胶而言,硫化可以改变其性质,从低模量,低拉伸强度,低硬度及高拉伸率到高模量,高拉伸强度,高硬度及低拉伸率;Thus, polymers may be classified as noncrosslinked and crosslinked, and this definition agrees generally with the subclassification in thermoplastic and thermoset polymers. 这样,聚合物可以分为非交联和交联的,这个定义与把聚合物细分为热塑性和热固性聚合物相一致; From the mechanistic point of view, however, polymers are properly divided into addition polymers and condensation polymers. Both of these species are found in rubbers, plastics, and fibers. 然而,从反应机理的观点看,聚合物可以分成加聚物和缩聚物;这些种类聚合物在塑料,橡胶和纤维中都可以找得到;In many cases polymers are considered from the mechanistic point of view. Also, the polymer will be named according to its source whenever it is derived from a specific hypothetical monomer, or when it is derived from two or more components which are built randomly into the polymer. 在许多情况下,聚合物可以从反应机理的角度考虑分类; 每当聚合物来自于一个假象单体,或来自于两个或两个以上组成物无规则构建聚合物时,也可以根据聚合物的来源来命名; This classification agrees well with the presently used general practice. 这种分类方法与目前实际情况相符合;When the repeating unit is composed of several monomeric components following each other in a regular fashion, the polymer is commonly named according to its structure. 当重复单元由几个单体组成物规则排布,聚合物通常根据它的结构来命名;It must be borne in mind that, with the advent of Ziegler-Natta mechanisms and new techniques to improve and extend crystallinity, and the closeness of packing of chains, many older data given should be critically considered in relation to the stereoregular and crystalline structure. 必须记住,随着Ziegler-Natta机理,以及提高结晶度和链堆砌紧密度新技术的出现,对许多过去已经得到的关于空间结构和晶体结构旧的资料,应当批判地接受;The properties of polymers are largely dependent on the type and extent of both stereoregularity and crystallinity. As an example, the densities and melting points of atactic and isotactic species are presented in Table . 聚合物的性质主要依靠立体规整性和结晶度的类型和程度;如,无规立构和全同立构物质的密度和熔点展示在表中 ;UNIT11 Functional PolymersFunctional polymers are macromolecules to which chemically functional groups are attached; they have the potential advantages of small molecules with the same functional groups. 功能聚合物是具有化学功能基团的大分子,这些聚合物与具有功能聚合物是具有化学功能基团的大分子, 相同功能基团的小分子一样具有潜在的优点;Their usefulness is related both to the functional groups and to the nature of the polymers whose characteristic properties depend mainly on the extraordinarily large size of the molecules.它们的实用性不仅与功能基团有关,而且与巨大分子尺寸带来的聚合物特性有关;The attachment of functional groups to a polymer is frequently the first step towards the preparation of a functional polymer for a specific use. 把功能基团连接到聚合物上常常是制备特殊用途功能高分子的第一步;However, the proper choice of the polymer is an important factor for successful application. 然而,对成功应用而言,选择适当的聚合物是的一个重要因素;In addition to the synthetic aliphatic and aromatic polymers, a wide range of natural polymers have also been functionalized and used as reactive materials. 除了合成的脂肪组和芳香组聚合物之外,许多天然高分子也被功能化,被用做反应性材料;Inorganic polymers have also been modified with reactive functional groups and used in processes requiring severesi’vi service conditions. 无机聚合物也已经用反应功能基团改性,被用于要求耐用条件的场合;In principle, the active groups may be part of the polymer backbone or linked to a side chain as a pendant group either directly or viavai a space rs’peis group. 理论上讲,活性基团可以是聚合物主链上的一部分,或者直接连接到侧链或通过一个中间基团的侧基;A required active functional group can be introduced onto a polymeric support chain 1 by incorporation during the synthesis of the support itself through polymerization or copolymerization of monomers containing the desired functional groups, 2 by chemical modification of a nonfunctionalized performed support matrix and 3 by a combination of 1 and 2. 所需的活性功能基团可以通过几种方法引入到聚合物主链上, 1在主链的合成过程中,通过聚合或共聚合含有理想功能基团的单体来获得,2通过对已有的非功能化主链进行化学改性的方法,3通过结合1和2来获得;Each of the two approaches has its own advantages and disadvantages, and one approach may be preferred for the preparation of a particular functional polymer when the other would be totally impractical.两种途径中的每一种都有自身的优点和缺点,对特殊功能聚合物的制备而言,当其他方法都无法实现时,所选的方法或许是更合适的;The choice between the two ways to the synthesis of functionalized polymers depends mainly on the required chemical and physical properties of the support for a specific application. 功能聚合物合成的两种方法中,如何选择主要取决于特殊应用要求的主链聚合物的化学和物理性质;Usually the requirements of the individual system must be thoroughly examined in order to take full advantage of each of the preparative techniques. 为了充分利用每种制备方法,必须全面地考察独立体系的要求;Rapid progress in the utilization of functionalized polymeric materials has been noted in the recent past. 近年来,功能化聚合物材料的使用方面有了飞速的发展;Interest in the field is being enhanced due to the possibility of creating systems that combine the unique properties of conventional active moieties and those of high molecular weight polymers. 由于能够制造出来兼有活性官能团特性和高分子量聚合物性能的功能聚合物,所以,人们对功能聚合物这个领域的兴趣与日俱增;The successful utilization of these polymers are based on the physical form, solution behavior, porosity, chemical reactivity and stability of the polymers. 这些聚合物的成功利用,基于功能聚合物的物理形态,溶液行为,空隙率,化学活性及稳定性;The various types of functionalized polymers cover a broad range of chemical applications, including the polymeric reactants, catalysts, carriers, surfactants, stabilizers,ionexchange resins, etc.各种功能化聚合物类型覆盖化学应用的宽广领域,包括聚合物试剂,催化剂, 载体,表面活性剂,稳定剂,离子交换树脂等;In a variety of biological and biomedical fields, such as the pharmaceutical, agriculture, food industry and the like, they have become indispensable materials, especially in controlled release formulation of drugs and agrochemicals. 在生物学及生物医学领域中,如药物,农业,食品工业等, 在生物学及生物医学领域中,如药物,农业,食品工业等,功能聚合物是不可缺少的材料,尤其在药物和农药的控制释放配方上;Besides, these polymers are extensively used as the antioxidants, flame retardants, corrosion inhibitors, flocculating agents, antistatic agents and the other technological applications. 此外,这些聚合物被广泛地用做抗氧化剂,阻燃剂,缓蚀剂, 絮凝剂,抗静电剂及其他技术应用;In addition, the functional polymers possessp’zes broad application prospects in the high technology area as conductive materials, photosensitizers, nuclear track detectors, liquid crystals, the working substances for storage and conversion of solar energy, etc. 另外,功能化聚合物在高科技领域具有广阔的应用前景; 如导电材料,光敏剂,核径迹探测器,液晶,用于太阳能等的转化与储存的工作物质;第十二单元实验室制备氨基树脂氨基树脂是由氨基衍生物和醛在酸性或碱性条件下反应生产得到的其中最重要最具代表性的物质是脲醛树脂和蜜胺树脂; 药品：尿素,福尔马林37%,乙醇,2N NaOH, NaOH溶液,1N标准NaOH溶液,1N标准HCl溶液,冰醋酸,糠醇,三乙醇胺,木粉,磷酸钙,氯化铵, H2SO4溶液,Na 2SO3,1%乙醇百里酚酞指示剂溶液,三聚氰胺,甘油和单羟甲基脲; 装置：烧瓶和烧杯,500ml的三口烧瓶,加热套,机械搅拌器,冷凝器,迪安—斯达克塔分水器,烘箱,广泛试纸,试管,250mL的容量烧瓶,冰浴,10ml 的移液管,滴管,油浴和广口瓶; 酸性条件下制备脲醛树脂：为了证明尿素和甲醛在酸性条件下的迅速反应,将5 g尿素和6 mL福尔马林在试管中混合,振荡试管直到尿素全部溶解;滴加4滴 N H2SO4以调节溶液pH到4,观察析出沉淀所需要的时间,取出部分沉淀并比较此沉淀以及单羟甲基脲样品在水中的溶解性;制备脲醛树脂粘合剂：将600g1mole尿素和137g福尔马林放入500ml三口烧瓶中,并安装好机械搅拌器和回流冷凝器,通过用广泛试纸测定用2NNaOH溶液把混合物PH值调至7~~8,然后将混合物回流2小时;1每隔半小时用下面的方法测定一次混合物中的自由甲醛含量,直到水完全脱除为止;2 当混合物回流2小时后,将迪安—斯达克塔分水器安装在烧瓶和回流冷凝器之间 ;大约有40ml水被蒸馏,用5滴冰醋酸将溶液酸化；将44g糠醇和的三乙醇胺加入到反应混合液中,加热此溶液到90℃并恒温15分钟;将混合物冷却到室温;取出15g的树脂样品和由1g木粉,磷酸钙和氯化铵组成的硬化剂混合 ;将混合物进行室温固化;3将剩下的没有加工硬化剂的树脂放入广口瓶中并提交给实验导师;自由甲醛含量的测定：自由甲醛含量的测定：准备250mL 1N Na2SO3溶液,并中和该溶液,从而使其产生淡蓝色的百里酚酞指示剂溶液;在250ml锥形瓶中加入重为2到3克的树脂样品到100mL的水中,摇晃锥形瓶使锥形瓶内的溶液充分溶解;如果树脂不能溶解,加入乙醇可以帮助溶解;在冰浴中使溶液的温度下降到4℃,加25mL的1M Na2SO3溶液在100mL的烧瓶中,用移液管移取10ml标准的1N HCl溶液到烧瓶中,降温至4℃;加10-15滴百里酚酞指示剂溶剂到样品烧瓶中,调整溶液的颜色至淡蓝色;用冷水冷却以后迅速地转移酸式亚硫酸盐溶液到样品烧瓶中;4滴定溶液到百里酚酞的终点标准1N NaOH 溶液;CH2O+Na2SO3+H2O →CH2OHSO3-Na++NaOH通过中和树脂溶液的HCl溶液的量来测定自由甲醛的百分含量;三聚氰胺甲醛树脂的制备：在一个500ml的配置有机械搅拌器和一个冷凝器的反应器中加入63g 的三聚氰胺和122g的福尔马林37%;混合物回流40分钟;%自由甲醛需要每隔十分钟测定一次;自由甲醛的测定步骤如上所述;样品经过20分钟加热后,在烧瓶和冷凝器间插入一个迪安—斯达克分水器,从而有10mL的水被蒸馏掉;把未固化的样品放入螺丝帽的坛子中,连同固化的树脂一起交给实验指导老师;15单元到目前为止大多数的PVC生产通过悬浮聚合;在这个过程中,氯乙烯单体悬浮液体滴,在连续水相剧烈的搅拌和保护胶体的悬浮剂;使用单体溶自由基引发剂polymeri等自下而上发生在悬浮液滴内,通过一个机制,已被证明相当于本体聚合;商业植物是基于批量反应堆,这增加了支持的大小,多年来;原来的工厂建于1940年代通常由IOOO 加仑反应堆;在1960年代和1950年代这t0 3000一5000加仑和增加随后,在1970年代初,29000加仑反应堆系统开发的胫完全②,t0 44000加仑200立方米的德国公司Huls;目前一些新的工厂正在建造的反应堆由不到isooo加仑容量,有一个批处理大小约25吨单体;小型反应堆通常衬玻璃给光洁度,抵制存款的搁置在墙上;~大反应堆通常的抛光不锈钢;氯乙烯的聚合反应是一个放热反应的能力,移走热量通常试图减少反应时间的限制因素;随着规模的反应堆已经增加了表面积体积比,因此加重这一问题;内部冷却线圈通常不用作吸引存款和很难清洁,从而对产品性能有不利影响;问题通常是克服使用冷冻水或回流冷凝器的装置,通过氯乙烯单体的连续回流;利用其潜热冷却的目的;一个简单的悬浮聚合配方可能包含以下成分:冷水通常是首先向反应堆虽然有时预热;然后添加pH值调节剂紧随其后的是分散剂的形式解决方案;发起者年代立即撒到水相的表面密封反应堆然后撤离前去除氧,因为这可以增加聚合时间,影响产品性能;当引发反应完成乙烯氯化物被指控和加热反应堆的内容开始;反应但真正的,产品分子量的主要控制因素;通常是在50——70 'c导致反应堆压力范围100 - 165 psi;趋势是朝着大的操作只打开关闭反应堆维护或可能偶尔打扫道;”:在这种情况下所有的原料都是负责解决方案或分散体,一般不需要疏散的一步;当达到所需的转换了,通常75%一95%,反应可以如果需要化学short-stopped和剩余的大部分单体恢复;他产品泥浆然后剥下来非常低的残留氯乙烯治疗-水平表示“状态”姆温度升高,在反应堆或类似容器,或接触蒸汽在逆流多平台汽提塔;然后脱水离心法和由此产生的泥浆湿饼乾,多级闪蒸干燥机一般,虽然各种不同的干燥类型使用不同的生产;干燥后,产品是通过某种剥皮屏幕去除无关的大颗粒装袋之前或装载散装油轮;—T 16 Styrene-Butadiene Copolymer第十六单元丁二烯-苯乙烯共聚物合成橡胶工业,以自由基乳液过程为基础,在第二次世界大战期间几乎很快地形成;那时,丁苯橡胶制造的轮胎性能相当优越,使天然橡胶在市场黯然失色;丁苯橡胶的标准制法是组分重量分数组分重量分数丁二烯72 过硫酸钾苯乙烯25 肥皂片十二烷基硫醇水180 混合物在搅拌下50℃加热,每小时转化5%～6%,在转化率达70%～75%时通过加入“终止剂”聚合反应终止,例如对苯二酚大约的重量百分含量,抑制自由基并避免过量支化和微凝胶形成;未反应的丁二烯通过闪蒸去除,苯乙烯在萃取塔中通过蒸汽萃取剥离;在加入抗氧剂后,例如N-甲基-β-萘胺的重量百分含量,加入盐水,其次加入稀释的硫酸或硫酸铝后乳液凝胶;凝胶碎片被洗涤、干燥。
高分子材料工程专业英语翻译完整版本
第一单元什么是高聚物？什么是高聚物？首先，他们是合成物和大分子，而且不同于低分子化合物，譬如说普通的盐。
与低分子化合物不同的是，普通盐的分子量仅仅是58.5，而高聚物的分子量高于105，甚至大于106。
这些大分子或“高分子”由许多小分子组成。
小分子相互结合形成大分子，大分子能够是一种或多种化合物。
举例说明，想象一组大小相同并由相同的材料制成的环。
当这些环相互连接起来，可以把形成的链看成是具有同种分子量化合物组成的高聚物。
另一方面，独特的环可以大小不同、材料不同，相连接后形成具有不同分子量化合物组成的聚合物。
许多单元相连接给予了聚合物一个名称，poly意味着“多、聚、重复”，mer意味着“链节、基体”（希腊语中）。
例如：称为丁二烯的气态化合物，分子量为54，化合将近4000次，得到分子量大约为200000被称作聚丁二烯（合成橡胶）的高聚物。
形成高聚物的低分子化合物称为单体。
下面简单地描述一下形成过程：丁二烯＋丁二烯＋…＋丁二烯——→聚丁二烯（4000次）因而能够看到分子量仅为54的小分子物质（单体）如何逐渐形成分子量为200000的大分子（高聚物）。
实质上，正是由于聚合物的巨大的分子尺寸才使其性能不同于象苯这样的一般化合物。
例如，固态苯，在5.5℃熔融成液态苯，进一步加热，煮沸成气态苯。
与这类简单化合物明确的行为相比，像聚乙烯这样的聚合物不能在某一特定的温度快速地熔融成纯净的液体。
而聚合物变得越来越软，最终，变成十分粘稠的聚合物熔融体。
将这种热而粘稠的聚合物熔融体进一步加热，不会转变成各种气体，但它不再是聚乙烯（如图1.1）。
固态苯——→液态苯——→气态苯加热，5.5℃加热，80℃固体聚乙烯——→熔化的聚乙烯——→各种分解产物-但不是聚乙烯加热加热图1.1 低分子量化合物（苯）和聚合物（聚乙烯）受热后的不同行为发现另一种不同的聚合物行为和低分子量化合物行为是关于溶解过程。
例如，让我们研究一下，将氯化钠慢慢地添加到固定量的水中。
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介绍高分子的英语作文
介绍高分子的英语作文Polymer is a fascinating material that can be found in various aspects of our daily lives. Take a look around you, and you will surely spot something made of polymer. Fromthe plastic bottles we use to the rubber soles on our shoes, polymers are everywhere.Speaking of plastic bottles, they are a perfect example of how versatile polymers can be. These bottles are made of a type of polymer called polyethylene terephthalate, or PET for short. PET is lightweight, durable, and resistant to breakage, making it an ideal material for packaging beverages. Plus, it can be easily molded into different shapes and sizes, allowing for a wide range of bottle designs.Another interesting use of polymers is in the field of medicine. Medical-grade polymers, such as polyethylene and polypropylene, are commonly used in the manufacturing of medical devices and implants. These polymers arebiocompatible, meaning they can be safely used in the human body without causing any harm. They are also resistant to chemicals and sterilization methods, ensuring the safetyand effectiveness of medical procedures.Polymers are also widely used in the construction industry. One example is polyvinyl chloride, or PVC, whichis used in the production of pipes, window frames, and flooring materials. PVC is lightweight, durable, and resistant to moisture, making it an excellent choice for building materials. Additionally, it can be easily molded and shaped, allowing for customized designs and easy installation.In the world of fashion, polymers play a significantrole as well. Synthetic fibers, such as polyester and nylon, are made from polymers and are commonly used in the production of clothing and accessories. These fibers are lightweight, strong, and resistant to wrinkles, making them highly desirable for creating comfortable and long-lasting garments. Moreover, they can be easily dyed and printed, offering a wide range of colors and patterns for fashiondesigners to work with.In conclusion, polymers are incredibly versatile materials that have revolutionized various industries. From plastic bottles to medical devices, construction materials to fashionable clothing, polymers have become an essential part of our modern lives. Their unique properties and adaptability make them the go-to choice for many applications. So next time you come across a polymer product, take a moment to appreciate the science and innovation behind it.。
高分子材料与工程英语自我介绍
高分子材料与工程英语自我介绍Self-Introduction.Hello, esteemed panel, it's a pleasure to have this opportunity to introduce myself. My name is [Your Name],and I come from [Your City/Town], a place renowned for its [Any Notable Feature or Landmark]. My academic journey has been an exciting and enriching experience, centered around the field of Polymer Materials and Engineering.My interest in polymers and their applications stemmed from my early exposure to the world of science and technology. The versatility and widespread use of polymersin our daily lives, from packaging materials to medical implants, fascinated me. This curiosity led me to pursue a degree in Polymer Materials and Engineering, a field that combines the best of chemistry, physics, and engineering.During my undergraduate studies, I had the opportunityto delve into the fundamental principles of polymer science.I was introduced to the chemistry of polymer synthesis, the physics of polymer chains, and the engineering challenges associated with processing and applications. My favorite part of the program was the laboratory work, where I could apply theoretical concepts to practical problems. I conducted several experiments on polymer synthesis and characterization, gaining valuable hands-on experience.To further expand my knowledge and skills, I pursued a graduate degree in Polymer Engineering. This program provided me with a more comprehensive understanding of polymer processing, polymer composites, and advanced materials. I was exposed to cutting-edge research in the field, which helped me develop a critical understanding of the latest advancements in polymer technology.My graduate research focused on the development of novel polymer-based composites for enhanced mechanical properties. Under the guidance of my advisor, I designed and synthesized new polymer systems, evaluated their performance, and optimized their processing parameters. This research not only honed my experimental skills butalso taught me the importance of problem-solving and innovative thinking in engineering.Apart from academic pursuits, I have also gained valuable industrial experience. I worked as a research associate at [Name of the Company], where I was involved in the development of polymer-based products for the automotive industry. This experience gave me insights into the industrial scale-up of polymer processes and the challenges associated with product development and commercialization.My strengths lie in my ability to bridge theory and practice, my dedication to continuous learning, and my enthusiasm for solving complex problems. I am proficient in polymer characterization techniques such as FTIR, NMR, and DSC, and I am also skilled in computational modeling and simulation.In conclusion, my academic background, research experience, and industrial exposure have provided me with a solid foundation in Polymer Materials and Engineering. I amexcited about the opportunities this field offers and am eager to contribute to its continued growth and development. Thank you for considering my application. I look forward to the possibility of further discussing my qualifications and how I can contribute to your team.。
高分子链的结构
"for discovering that methods developed for studying order phenomena in simple systems can be generalized to more complex forms of matter, in particular to liquid crystals and polymers"
CH2
CH
CH
CH3
n
CH2
C CH3
CH
CH3
n
聚氯乙烯
PVC
CH2
H C Cl
n
Polyvinyl Chloride 聚偏二氯乙烯 PVDC
CH2
Cl C Cl
CF2 CF2
n
Polyvinylidene Chloride PTFE 聚四氟乙烯 Polytetrafluoroethylene Teflon 聚丙烯腈 PAN Polyacrylonitrile POM 聚甲醛 Polyformaldehyde
Karl Ziegler (1903-1979)
Giulio Natta (1898-1973)
"for their discoveries in the field of the chemistry and technology of high polymers"
• 1974, Paul J. Flory
• 高分子 聚合物)与大分子 高分子(聚合物 与大分子 聚合物 • Polymer and Macromolecule • 高分子材料
高 分 子 按 用 途 可 分 为 ：
• 塑料
– 热固性塑料 (酚醛树脂、脲醛树脂 酚醛树脂、 酚醛树脂 脲醛树脂) – 热塑性塑料 (PE, PP, PVC, PS, PMMA, 尼龙) 尼龙
国外高分子物理英文教材研究
国外高分子物理英文教材研究1. "Introduction to Polymers"作者：Robert J. Young 和 Peter A. Lovell这本教材是高分子物理学领域的经典教材之一，被广泛用于高校教育和高分子材料的研究。
本书详细介绍了高分子的物理化学特性和应用，包括高分子结构、合成、物理性质、加工和应用。
它的编排清晰，符合知识的层次性和系统性，便于帮助读者理解和掌握高分子物理学的基本知识和实际应用。
本书是一个广泛阐述高分子物理学和聚合物材料科学的教材，并且适用于物理学、化学、生物学和工程专业学生。
本书结合了物理、化学和数学的原理，介绍了高分子的结构、物性和应用。
该书还着重于聚合物动力学的理论和实践，并将聚合物的行为与自然界中的相似行为进行了比较。
这本名为《高分子材料的力学》的书介绍了当今工程和科学实践中的膜、纤维、塑料和弹性材料的机械性能。
本书更新了高分子物理学的啮合理论，并探讨了不同的高分子纤维类型的力学行为。
此外，还介绍了高分子材料的断裂和损耗以及微观和宏观观测之间的联系。
本书是一本深入了解高分子混合物和复合材料的教材。
它详细介绍了高分子混合物和复合材料的优缺点、原理、制备和应用。
在介绍高分子混合物和复合材料的基础知识的基础上，还介绍了涉及高分子复合材料的专业领域，如航空、汽车、电子、医疗和运动用品，这学员可以更深入地了解高分子物理学与现代科技产业之间的联系。
以上这些教材都是用于高校教育和高分子科技研究的经典教材，涉及高分子物理学的重要方面，从基础概念到高级应用全面详尽。
这些教材都是由多位高分子物理学家共同编撰而成，可供从学生到专业领导人使用，任何人都可以从这些教材中获得广泛的知识，对高分子物理学的科学和技术应用有更深入的了解和掌握。
Introduction to Fluoropolymers
4Introduction to Fluoropolymers Sina Ebnesajjad,PhDFluoroConsultants Group,LLC4.1IntroductionFluoropolymer is usually olefinic polymer which consists of partially or fullyfluorinated olefinic monomers such as vinylidenefluoride(CH2¼CF2)and tetrafluoroethylene (TFE)(CF2¼CF2).These polymers have been covered ingreat detail in a number of references(see General Refer-ences).More specialtyfluorinated polymers include per-fluoroethers,fluoroacrylates,andfluorosilicones which are used in significantly smaller volume than olefinicfluo-ropolymers.Thesefluoropolymers and others are covered in detail elsewhere[1,2].Commercialfluoropolymers include homopolymers and copolymers.Homopolymers contain99%or more by weight one monomer and1%or less by weight of another monomer according to the convention by American Society for Testing Materials(ASTM).Copolymers contain more than1%or more by weight of one or more comonomers.The major commercialfluoropolymers are based on three monomers: TFE,vinylidenefluoride(VF2),and to a lesser extent chlorotrifluoroethylene(CTFE).Examples of comonomers include perfluoromethyl vinyl ether(PMVE),perfluoroethyl vinyl ether(PEVE),perfluoropropyl vinyl ether(PPVE), hexafluoropropylene(HFP),CTFE,perfluorobutyl ethylene (PFBE),and exotic monomers such as2,2-bistri-fluoromethyl-4,5-difluoro-1,3-dioxole.Thefluoropolymers reviewed in this chapter include polytetrafluoroethylene(PTFE),perfluoroalkoxy polymer (PFA),fluorinated ethylene e propylene polymer(FEP),eth-ylene e tetrafluoroethylene copolymer(ETFE),ethylene e chlorotrifluoroethylene copolymer(ECTFE),polychlorotri-fluoroethylene(PCTFE),polyvinylidenefluoride(PVDF), and polyvinylfluoride(PVF).Classification,preparation, properties,fabrication,safety considerations,and economics offluoropolymers are reviewed.Monomer synthesis and properties have also been discussed.A good rule of thumb to remember is that increasing the fluorine content of a polymer molecule increases its chemical and solvent resistance,flame resistance,and photostability; improves its electrical properties such as lower dielectric constant;lowers coefficient of friction;raises melting point; increases its thermal stability;and weakens its mechanical properties.Solubility of polymers in solvents usually decreases by increasing thefluorine content of the molecule.4.2Fluoropolymer ClassificationThe serendipitous discovery of PTFE in1938by Roy Plunkett of DuPont Company[3]began the era offluo-ropolymers.PTFE has found thousands of applications because of its unique properties.Variousfluoroplastics (Figure4.1)have been developed since the discovery of PTFE.A number of companies produce these plastics around the world(Tables4.1and4.2).Fluoropolymers are divided into two classes of perfluorinated and partiallyfluorinated polymers.Perfluorinatedfluoropolymers are homopolymers and copolymers of TFE.Some of the comonomers may contain a small amount of elements other than C or F.For example,PFA is a copolymer of TFE and per-fluoroalkyl vinyl ether that contains oxygen.R f is a per-fluoroalkyl group of C1e C4.PCTFE(1937)ETFE(1972)FEP(1960)PFA(1973)PVF(1949)PVDF(1948)AF(1985)ECTFE(1970)PerfluorinatedPartially FluorinatedFirst melt-processibleperfluoropolymerProperties similar to PTFEPTFE(1938)Figure4.1Evolution offluoropolymer development over time. (PCTFE¼polychlorotrifluoroethylene,PVDF¼polyvinylidene fluoride,PVF¼polyvinylfluoride,FEP¼fluorinated ethyle-ne e propylene polymer,ECTFE¼ethylene chlorotrifluoro-ethylene polymer,ETFE¼ethylene e tetrafluoroethylene polymer,PFA¼perfluoroalkoxy polymer,AF¼amorphousfluoropolymers).Applied Plastics Engineering HandbookCopyrightÓ2011Elsevier Inc.All rights reserved.49Partially fluorinated fluoropolymers contain hydrogen (H)or other atoms such as chlorine,in addition to fluorine and carbon.The most significant are homopolymers and copoly-mers of PVDF.There are also copolymers and homopoly-mers of chlorotrifluoroethylene (PCTFE),although some have elastomeric properties.Other significant fluoroplastics include ETFE,ECTFE,and PVF.4.3Polymer Development HistoryPTFE cannot be fabricated by melt-processing techniques because of its high viscosity (1010e 1012poise at 380 C).Melt-processible fluoropolymers have been developed by copolymerization of TFE.FEP,a copolymer of TFE and HFP,has a lower maximum continuous use temperature than PTFE(200 C vs.260 C)because of the deterioration of mechanical properties.PFA,a copolymer of TFE with PPVE or PEVE,offers thermal stability,melt-processibility and maximum continuous use temperature d 260 C.Both FEP and PFA are considered perfluoropolymers.Copolymers of ethylene with tetrafluoroethylene (ETFE)and chlorotrifluoroethylene (ECTFE)are mechanically stronger than perfluoropolymers,accompanied with trade-offs of reduction in their chemical resistance and continuous use temperature and an increase in the coefficient of friction.Amorphous copolymers of TFE are soluble in special halogenated solvents and can be applied to surfaces as a polymer solution to form thin coatings.The dried coating is as resistant to almost as many chemicals as PTFE.[4]4.4Monomer Synthesis4.4.1Synthesis of TetrafluoroethyleneThe first reliable and complete description of TFE synthesis was published in 1933by Ruff and Bretschneider [5]in which they prepared TFE (CF 2¼CF 2,CAS number 116-14-3)from decomposition of tetrafluoromethane in an electric arc.TFE was obtained by bromination and separation of the dibromide (CF 2Br e CF 2Br)from the other reaction products.Dehalogenation with zinc was the next step for obtaining pure mercially significant techniques for TFE preparation list fluorspar (CaF 2),hydrofluoric acid,and chloroform as the starting ingredients [6e 13],as shown in the reaction sequence in Figure 4.2.Among other compounds produced are HFP and a small amount of highly toxic perfluoroisobutylene.Sherratt [14]and others [15]have provided complete descriptions of the preparation of TFE.The overall yield of TFE production depends on the pyrolysis reaction.The products of pyrolysis are cooled,scrubbed with a dilute basic solution to remove HCl,and dried.The resulting gas isHF preparation:Chloroform preparation:Chlorodifluoromethane preparation:TFE synthesis:CaF 2 + H 2SO 4CH 4 + 3Cl 2CHCl 3 + 2HF 2CHClF 2 (pyrolysis)2=CF 2 + 2HCl(SbF 3 catalyst)CHClF 2 + 2HClCHCl 3 + 3HCl 2HF + CaSO 4Figure 4.2Synthesis reactions oftetrafluoroethylene.Table 4.1Global producers of fluoropolymersTable 4.2Global producers of fluoropolymers 50A PPLIED P LASTICS E NGINEERING H ANDBOOKcompressed and distilled to recover the unreacted CHClF2and high purity TFE.Polymerization of TFE to high molecular weight requires extreme purity,thus ensuring the removal of all traces of telogenic hydrogen or chlorine-bearing impuri-ties.TFE can autopolymerize if it is not inhibited by terpenes, such as a-pinene,terpene B,and d-limonene[16].4.4.2Synthesis ofHexafluoropropyleneHFP(CF3CF¼CF2,CAS number116-15-4)wasfirst prepared by Benning et al.[17]by pyrolysis.The full synthesis and identification of HFP was conducted by Henne[18].A six step reaction scheme starting with the fluorination of1,2,3-trichloropropane led to1,2-dichloro-hexafluoropropane.The latter was dehalogenated with zinc in boiling ethanol to yield HFP.HFP is a co-product in the synthesis of TFE.HFP yield can be increased,in lieu of TFE production,by altering the reaction conditions such as reduction in the pyrolysis temperature and use of steam as diluent of the reactants[19,20].4.4.3Synthesis of PerfluoroalkylVinyl EthersPerfluoroalkyl vinyl ethers such as perfluoropropyl vinyl ether(CF2¼CF e O e C3F7,CAS number1623-05-8)are synthesized according to the steps shown in Figure4.3as well as alternative techniques[21].There are other processes including electrochemical methods for the production of perfluoro-2-alkoxy-propionylfluoride[22].4.4.4Synthesis ofChlorotrifluoroethyleneThis monomer is fairly simple to manufacture compared to the perfluorinated monomers[25e28].The commercial process for the synthesis of CTFE(CF2¼CClF,CAS number 79-38-9)begins with1,1,2-trichloro-1,2,2-trifluoroethane (TCTFE).It is dechlorinated by pyrolysis at500e600 C in vapor phase.An alternative method for preparation of TCTFE is catalytic dechlorination:CCl3e CCl3þHF/CCl2F e CClF2þ2HClðcatalystSbCl x F yÞCCl2F e CClF2þZn/CFCl¼CF2þZnCl2ðat50e100 C in methanolÞThe reaction stream is put through a number of purifica-tion and distillation steps to remove the gaseous and liquid contaminants.CTFE is further purified by the removal of methyl chloride,dimethyl ether,and water by passing the gas stream through sulfuric acid.Water and hydrochloric acid are removed by passing the CTFE through an alumina column before condensing it into a liquid.4.4.5Synthesis of Vinylidene FluorideThere are numerous ways to prepare vinylidenefluoride (VDF)(CF2¼CH2,CAS number75-38-7)[29,30].Two Figure4.3Synthesis of perfluoroalkyl vinyl ethers[23e24].S.E BNESAJJAD51methods,including the popular commercial technique forVDF production,are described.Conversion of1,1,1-tri-fluoroethane[31]begins by passing this gas througha platinum-lined Inconel tube,which is heated to1200 C.Contact time is about0.01seconds.The exit gases arepassed through a sodiumfluoride bed to remove thehydrofluoric acid and are then collected in a liquidnitrogen trap.VDF is separated by low temperaturedistillation.Unreacted trifluoroethane is removed atÀ47.5 Cand is recycled.The commercial method begins with hydrofluorination ofacetylene followed by chlorination[32],by hydrofluorinationof trichloroethane[33],or by hydrofluorination of vinylidenechloride[34].In each case thefinal product,1-chloro-1,1-difluoroethane,is stripped of a molecule of hydrochloricacid to yield VDF.4.4.6Synthesis of Vinyl FluorideVinylfluoride(VF)(CHF¼CH2,CAS number75-02-5)[35e39]wasfirst prepared by the reaction of1,1-difluoro-2-bromoethane(CAS number359-07-9)with zinc.Mostapproaches to VF synthesis have employed reactions ofacetylene(CAS number74-86-2)with hydrogenfluoride(HF)either directly or utilizing catalysts.Other routes haveinvolved ethylene(CAS number74-85-1)and HF,pyrolysisof1,1-difluoroethane(CAS number624-72-6)andfluoro-chloroethanes,reaction of1,1-difluoroethane with acetylene,and halogen exchange of vinyl chloride(CAS number75-01-4)with HF[40e42].4.5Monomer Properties4.5.1Properties of TetrafluoroethyleneTetrafluoroethylene15,44is a colorless,odorless,taste-less,nontoxic gas which boils atÀ76.3 C and melts at À142.5 C.The critical temperature and pressure of TFE are 33.3 C and3.92MPa.TFE is stored as a liquid;vaporpressure atÀ20 C is1MPa.Its heat of formation is reportedto beÀ151.9kcal/mole.Polymerization of TFE is highlyexothermic and generates41.12kcal/mole heat d the extentof which can be compared with the heats of polymerizationof vinyl chloride and styrene,at23e26kcal/mole and16.7kcal/mole,respectively.Safe storage of TFE requires its oxygen content to be lessthan20ppm.Temperature and pressure should be controlledduring its storage.Increasing the temperature,particularly athigh pressures,can initiate deflagration in the absence of air(TFE degrades into carbon tetrafluoride).In the presence ofair or oxygen,TFE forms explosive mixtures in the molarpercentage range of14e43%[44].Detonation of a mixtureof TFE and oxygen can increase the maximum pressure to100times the initial pressure.4.5.2Properties ofHexafluoropropyleneHexafluoropropylene is a colorless,odorless,tasteless, and relatively low toxicity gas,which boils atÀ29.4 C and freezes atÀ156.2 C.In a4-hour exposure,a concentration of3000ppm corresponded to LC50in rats[45,46].Critical temperature and pressure of HFP are85 C and3254MPa. Unlike TFE,HFP is extremely stable with respect to auto-polymerization and may be stored in liquid state without the addition of telogen.HFP is thermally stable up to400e500 C. At about600 C under vacuum,it decomposes and produces octafluoro-2-butene(CF3CF¼CFCF3)and octa-fluoroisobutylene[47].4.5.3Properties of Perfluoroalkyl Vinyl EthersPerfluoroalkyl vinyl ethers(PA VE)form[22]an important class of monomers in that they are comonomers of choice for the“modification”of the properties of homofluoropolymers in addition to broad use in the structure of copolymers of TFE.The advantage of PA VEs as modifiers over HFP is their remarkable thermal stability.A commercially significant example is per-fluoropropyl vinyl ether(PPVE).PPVE is an odorless,colorless liquid at room temperature.It is extremelyflammable and burns with a colorlessflame.It is less toxic than HFP.4.5.4Properties ofChlorotrifluoroethyleneChlorotrifluoroethylene is a colorless gas at room temperature and pressure.It is fairly toxic with an LC50(rat) at4-hour exposure and a concentration of4000ppm[49]. It has a critical temperature and pressure of105.8 C and4.03 MPa.Oxygen and liquid CTFE react and form peroxides at fairly low temperatures.A number of oxygenated products, such as chlorodifluoroacetylfluoride,are generated by oxidation of CTFE[48].The same reaction can occur photochemically in the vapor phase.Chlorotrifluoroethylene oxide is a by-product of this reaction.The peroxides act as initiators for the polymerization of CTFE,which can occur violently.4.5.5Properties of Vinylidene FluorideVinylidenefluoride,(CH2¼CF2),is[49]flammable and is a gas at room temperature.It is colorless and almost odorless and boils atÀ84 C.VDF can form explosive mixtures with air.Polymerization of this gas is highly exothermic and takes place above its critical temperature and pressure.4.5.6Properties of Vinyl FluorideVinylfluoride(75-02-5)(fluoroethene)is a colorless gas at ambient conditions[38].It isflammable in air between the limits of2.6and22%by volume.Minimum ignition52A PPLIED P LASTICS E NGINEERING H ANDBOOKtemperature for VF and air mixtures is400 C.Adding a trace amount(<0.2%)of terpenes is effective to prevent spontaneous polymerization of VF.Inhibited VF has been classified as aflammable gas by the U.S.Department of Transportation.4.6Polymerization and Finishing4.6.1Polytetrafluoroethylene,PTFE (CAS number9002-84-0)PTFE is produced[43,50]by free-radical polymerization mechanism in an aqueous media via addition polymeriza-tion of TFE in a batch process.The initiator for the poly-merization is usually a water-soluble peroxide such as ammonium persulfate or disuccinic peroxide.A redox catalyst is used for low temperature polymerization.PTFE is produced by suspension(or slurry)polymerization without a surfactant to obtain granular resins or with a perfluorinated surfactant(emulsion polymerization)such as ammonium perfluorooctanoate to producefine powder and dispersion products.Polymerization temperature and pressure usually range from0to100 C and0.7to 3.5MPa.See Section4.11for information about ammonium perfluorooctanoate.Granular PTFE is produced by polymerizing TFE alone or by using trace amounts of comonomers.A peroxide initiator, little or no surfactant,and other additives may be present in the aqueous polymerization medium that is vigorously stirred and sometimes buffered by an alkaline solution.Most of the polymer is formed in the gas phase in the shape of stringy and irregularly shaped particles.The particles are comminuted to different sizes,depending on the powder properties required by the fabrication process.For example,a smoother surface part requires smaller particle size while goodflow is improved by larger particle size.Fine powder PTFE is produced by polymerization of TFE in an aqueous medium in the presence of an initiator and surfactant.The polymerization does not follow a conventional emulsion mechanism but some of the prin-ciples,which apply.The stability of the dispersion during the polymerization,to avoid premature coagulation,is balanced against the need to break the emulsion to recover the PTFE.Low shear rate agitation is maintained during the polymerization using surfactant levels below the critical micelle concentration.The rate of polymerization and particle shape and size are affected by the concentration of the surfactant.Majority of the particles is generated in the early part of polymerization and grows as the cycle proceeds.Molecular weight and composition within the particle can be controlled using the polymerization ingre-dients and conditions.The same polymerization process makes aqueous disper-sions of PTFE asfine powder.The dispersion is concentrated and stabilized using a variety of ionic and nonionic surfac-tants.Several concentration methods have been reported including electrodecantation,evaporation,and thermal concentration.Chemical additives to match them with the fabrication process or part property requirements can modify thefinal PTFE dispersion.Filled compounds are produced from all three forms of PTFE usingfillers such as glassfiber,graphite,metal powder, carbonfiber,and others[50].4.6.2Perfluoroalkoxy Polymer,PFA (CAS number26655-00-5)PFA is a copolymer of TFE and perfluoroalkyl vinyl ether such as PPVE.Copolymerization of perfluoroalkyl vinyl ethers with TFE can be done in a halogenated solvent[51,52] in an aqueous phase[53]sometimes containing some halo-genated solvent,usually in the absence of a surfactant[54]. Terpolymers of this class contain other monomers such as HFP.Commercially,PFA is polymerized by free-radical polymerization mechanism usually in an aqueous media via addition polymerization of TFE and PPVE.The initiator for the polymerization is usually water-soluble peroxide such as ammonium persulfate.Chain transfer agents such as methanol and acetone are used to control the molecular weight of the resin.Generally,the poly-merization regime resembles that used to produce PTFE by emulsion polymerization.Polymerization temperature and pressure usually range from15to95 C and0.5to 3.5MPa.End groups are stabilized by treating the PFA with methanol,ammonia,amines,and elementalfluorine that produces CF3end groups[55e59].The polymer is recov-ered,dried,and melt-extruded into cubes for melt fabrication processes.PFA is also available in bead(as polymerized), dispersion,andfine powder forms.4.6.3PerfluorinatedEthylene e Propylene Copolymer,FEP (CAS number25067-11-2)FEP is a random copolymer of TFE and HFP which can be polymerized,in an aqueous or a nonaqueous media[54,60]. Terpolymers of this class contain other monomers such as perfluoroalkyl vinyl ether(e.g.,PPVE)to improve stress crack resistance.Commercially,it is polymerized by free-radical poly-merization mechanism usually in an aqueous(or nonaqueous)media via addition polymerization of TFE and HFP.The initiator for the polymerization is usually water-soluble peroxide such as potassium persulfate.Chain transfer agents could be used to control the molecular weight of the resin.In general,the polymerization regime and conditionsS.E BNESAJJAD53resemble those used to produce PTFE by emulsion poly-merization.FEP is recovered,dried,and melt-extruded into cubes for melt fabrication processes.FEP is also available in dispersion form.4.6.4Ethylene e Co-tetrafluoroethylene Polymers,ETFE(CAS number68258-85-5)This plastic is a partiallyfluorinated straight-chain poly-mer with very high molecular weight[56].It is produced by free-radical polymerization mechanism in a solvent or a hybrid(a solvent/aqueous mixture)media,using an organic peroxide initiator.Copolymerization of TFE and ethylene (CH2¼CH2,molecular weight28,CAS number74-85-1) proceeds by an addition mechanism.Copolymers of TFE and ethylene are highly crystalline and fragile at elevated temperatures and are modified by a third monomer.Production of ETFE terpolymers having improved high-temperature mechanical(especially tensile) properties has been demonstrated[63].They comprise of 40e60mole%ethylene,40e60%TFE,and a small amount of a polymerizable vinyl termonomer such as per-fluoroisobutylene,PPVE,and HFP.4.6.5Ethylene e Co-chlorotrifluoroethylene Polymers, ECTFE(CAS number25101-45-5) This polymer is formed by the polymerization of ethylene and CTFE[64]in aqueous and solvent mediums using organic peroxides and oxygen-activated triethylboron. Typical polymerization is done at60e120 C and a pressure of5MPa or higher.The polymerization reaction can also be initiated by radiation like gamma rays.The most effective catalyst is tri-n-butyl boron which produces an ECTFE with an alternating1:1ethylene to TFE ratio.To control the molecular weight of the resin,chain transfer agents such as chlorinated compounds,alcohols,and ketones are required.4.6.6Polychlorotrifluoroethylene, PCTFE(CAS number9002-83-9) CTFE is polymerized by bulk,suspension,and emulsion techniques[65].Bulk polymerization takes place using halogenated acyl peroxide catalysts or UV and gamma rays. Suspension polymerization is carried out in aqueous medium using inorganic or organic peroxide catalysts.Emulsion polymerization yields a polymer with a normal molecular weight distribution and a molecular weight e melt viscosity relationship similar to bulk polymerized polymer.Inorganic peroxy catalysts initiate the reaction in the presence of halogenated alkyl acid salt surfactants.Emulsion polymeri-zation produces the most thermally stable PCTFE.4.6.7Polyvinylidene Fluoride,PVDF (CAS number24937-79-9)Thefirst successful aqueous polymerization of VDF was reported in1948[66]using a peroxide initiator in water at 50e150 C and30MPa.No surfactants or suspending agents were present in the polymerization recipe.PVDF has been polymerized by a number of methods including emulsion, suspension,solution,and ter,copolymers of VDF with ethylene and halogenated ethylene monomers were also produced[67].In1960,a manufacturing process was developed and PVDF wasfirst introduced to the market. Reaction temperature ranges from10to150 C at pressure of 1MPa or higher.Similar to TFE,emulsion polymerization of VDF requires a stablefluorinated surfactant and an initiator such as peroxide or persulfate.Suspension polymerization is conducted in an aqueous medium sometimes in the presence of a colloidal dispersant such as a hydroxy cellulose.Solution polymerization of VDF in solvents using free radical initia-tors is another way of producing PVDF.PVDF is commer-cially produced by aqueous emulsion or suspension processes.4.6.8Polyvinyl Fluoride,PVF(CAS number24981-14-4)Vinylfluoride undergoes free-radical polymerization [39,68].Thefirst polymerization involved heating a saturated-solution of VF in toluene at67 C under600MPa for16hours. Awide variety of initiators and polymerization conditions have been explored.Examples of bulk and solution polymerizations exist;however,aqueous suspension or emulsion methods are generally preferred.Copolymers of VF and a wide variety of other monomers have been prepared.More recently, interpolymers of VF have been reported with TFE and other highlyfluorinated monomers such as HFP, perfluorobutylethylene,and perfluoroethyl vinyl ether.4.7Structure e Property RelationshipA way to understand the impact offluorine is to explore the differences between linear polyethylene(PE)and PTFE [37]which is the ultimatefluoropolymer in terms of prop-erties and characteristics.There are important differences between properties of PE and that of PTFE:PTFE is one of the lowest surface energy polymers PTFE is the most chemically resistant polymerPTFE is one of the most thermally stable polymersMelting point and specific gravity of PTFE are more than double those of polyethylenePTFE and PE differences are attributable to the differ-ences of C e F and C e H bonds.The differences in the54A PPLIED P LASTICS E NGINEERING H ANDBOOKelectronic properties and sizes of F and H lead to the following observations:F is the most electronegative of all elements (4Paulings) F has unshared electron pairsF is more easily converted to F eBond strength of C e F is higher than C e H F is larger than HThe electronegativity of carbon at 2.5Paulings is some-what higher than that of hydrogen (2.1Paulings)and lower than the electronegativity of fluorine.Consequently,the polarity of the C e F bond is opposite to that of the C e H bond,and the C e F bond is more highly polarized.In the C e F bond,the fluorine end of the bond is negatively charged compared to the C e H bond in which the carbon is negatively charged.The difference in bond polarity of C e H and C e F affects the relative stability of the conformations of the two polymer chains.Crystallization of polyethylene takes place in a planar and trans conformation.PTFE can be forced into such a conformation at extremely high pressure [66].PTFE,below 19 C,crystallizes as a helix with 0.169nm per repeat distance:it takes 13C atoms for a 180 turn to be completed.Above 19 C,the repeat distance increases to 0.195nm which means that 15carbon atoms are required for a 180 turn.At above 19 C the chains are capable of angular displacement,which increases above 30 C until reaching melting point (327 C).Substitution of F for H in the C e H bond substantially increases the bond strength from 99.5kcal/mole for the C e H bond to 116kcal/mole for the C e F bond.Consequently,thermal stability and chemical resistance of PTFE is higher than PE because more energy is required to break the C e F bond.The polarity and strength of the C e F bond render F atom abstraction mechanism for branching difficult.In contrast,highly branched polyethylene (>8branches per 100carbon atoms)can be synthesized.Branching mechanismas a tool to adjust crystallinity is not practical for PTFE.Instead comonomers with pendent groups have to be poly-merized with TFE.Crystallinity of never-melted PTFE is in the range of 92e 98%[28],consistent with an unbranched chain structure.FEP,a copolymer of TFE and HFP,has an as-polymerized crystallinity of 40e 50%.In FEP,the pendent CF 3group is bonded to a tertiary carbon that is less thermally stable than primary and secondary carbon atoms.Degradation curves (Figure 4.4)indicate degradation onset temperatures of 300 C for FEP (0.02%weight loss)and 425 C for PTFE (0.03%weight loss).4.8Polymer Properties of PTFE 4.8.1PTFE PropertiesPTFE has excellent properties such as chemical inertness,heat resistance (both high and low),electrical insulation properties,low coefficient of friction (static 0.08and dynamic 0.01),and nonstick property over a wide tempera-ture range (À260to þ260 C).It has a density in the range of 2.1e 2.3g/cm 3and melt viscosity in the range of 1e 10GPa persecond [44].Molecular weight of PTFE cannot be measured by standard methods.Instead,an indirect approach is used to judge molecular weight.Standard specific gravity (SSG)is the specific gravity of a chip prepared according to a standardized procedure.The underlying principle is that lower molecular weight PTFE crystallizes more extensively,thus yielding higher SSG values [67].PTFE that has not been previously melted has a crystal-linity of 92e 98%,indicating a linear and nonbranched molecular structure.Upon reaching 342 C,it melts changing from a chalky white color into a transparent amorphous gel.The second melting point of PTFE is 327 C because it never recrystallizes to the same extent as prior to its first melting.First-order and second-order transitions have been repor-ted for PTFE.The transitions that are close to room temperature are of practical interest because of impact on processing of the material.Below 19 C the crystalline system of PTFE is a nearly perfect triclinic.Above 19 C,the unit cell changes to hexagonal.In the range of 19e 30 C,the chain segments become increasing disorderly and the preferred crystallographic direction disappears,resulting in a large expansion in the specific volume of PTFE (1.8%)[68]which must be considered in measuring the dimensions of articles made from these plastics.PTFE is by far the most chemically resistant polymer among thermoplastics.The exceptions include molten alkali metals,gaseous fluorine at high temperatures and pressures,and few organic halogenated compounds such as chlorine trifluoride (ClF 3)and oxygen difluoride (OF 2).A few other chemicals have been reported to attack PTFE at or near its upper service temperature.PTFE reacts with 80%sodiumorFigure 4.4A comparison of thermal degradation of FEP and PTFE in air.S.E BNESAJJAD 55。
Polymer Science and Engineering
Polymer Science and Engineering Polymer Science and Engineering is a fascinating field that encompasses the study of polymers, their properties, and their applications. It involves the synthesis, characterization, and manipulation of polymers to create materials with desired properties for various industries. This interdisciplinary field combines elements of chemistry, physics, materials science, and engineering to develop new and improved materials that have a wide range of applications. One perspective to consider when discussing Polymer Science and Engineering is the impact it has on everyday life. Polymers are present in almost every aspect of our lives, from the plastic bottles we use to the synthetic fibers in our clothing. The development of new polymers and polymer-based materials has revolutionized industries such as packaging, automotive, electronics, and healthcare. For example, the development of biodegradable polymers has addressed the environmental concerns associated with plastic waste. This perspective highlights the importance of Polymer Science and Engineering in improving the quality of life and addressing societal challenges. Another perspective to consider is the role of research and innovation in Polymer Science and Engineering. Researchers in this field are constantly working towards developing new polymers with enhanced properties, such as improved strength, flexibility, and thermal stability. They also explore novel processing techniques to create materials with specific microstructures and properties. This perspective emphasizes the importance of scientific research and technological advancements in pushing the boundaries of what is possible in Polymer Science and Engineering. From an economic perspective, Polymer Science and Engineering play a significant role in driving innovation and economic growth. The development of new materials and technologies in this field has led to the creation of new industries and job opportunities. For example, the demand for lightweight and high-performance materials in the automotive industry has created a market for advanced polymer composites. This perspective highlights the potential for economic development and the importance of investing in research and education in Polymer Science and Engineering. In addition to its practical applications, Polymer Science and Engineering also has a profound impact on the environment. The production and disposal of polymers can have significant environmental consequences, such aspollution and resource depletion. However, researchers in this field are actively working towards developing sustainable and environmentally friendly polymers. This perspective emphasizes the need for sustainable practices and the importance of considering the environmental impact of polymer-based materials. Lastly, it is important to consider the ethical implications of Polymer Science and Engineering. The development of new materials and technologies raises ethical questions regarding their potential impact on society and the environment. For example, the use of polymers in medical devices raises concerns about their biocompatibilityand long-term effects on human health. This perspective highlights the need for responsible and ethical practices in Polymer Science and Engineering, ensuringthat the benefits outweigh the potential risks. In conclusion, Polymer Scienceand Engineering is a multidisciplinary field with a wide range of perspectives to consider. From its impact on everyday life to its role in research and innovation, this field plays a crucial role in improving the quality of life, driving economic growth, and addressing environmental challenges. However, it is important to approach Polymer Science and Engineering with a sense of responsibility and ethics, considering the potential impact on society and the environment. By doing so, we can harness the full potential of polymers and create a sustainable and prosperous future.。
罗德岛设计 学院(亦称RISD)是美国 艺术 与 设计 院校的先驱
罗德岛设计学院（亦称RISD）是美国艺术与设计院校的先驱。
目前大约有2,300名本国与外国全日制的学生在此就学。
我们的学士与硕士学位课程维持在19个主修科系，并拥有坚强的文科教学基础，如艺术史、文学、哲学、社会学。
身为专业艺术家与设计师的 RISD 系所教职員，以特殊实用的方式进行艺术教育。
他们与学生建立深厚的信赖关系并鼓励学生自我突破，利用新的方式去学习观察与思考，重新定义问题并批判传统方法。
RISD 教授透过严谨的画室課程，注重创作过程；在过程中，他们会提出精辟的问题，借以激励学生创作出拥有强烈自我风格的创新作品。
学生一旦精熟各种素材，就可发展自己的艺术观点，并且学得独立解決问题的技能。
因此，已经有超过 17,000 多位校友在各自的领域里开创一番新天地并在国际间扬名力挽，遍及的领域包括：建筑、室内建筑、景观建筑、产品、平面与展览设计；时装与纺织；娱乐、制片、出版；电影艺术、教学及其他诸多领域。
RISD创办于1877年，坐落在罗德岛的Providence，位于美国东岸，距离纽约市望北约3个小时的车程，波士顿往南约45分钟的车程。
Providence就像一座小型的新英格兰城市以其活跃的艺术学院、河滨公园、舒适的规模与多元文化的社区而自豪。
它是四所大学院校的发源地，包括RISD的常春藤联盟邻居布朗大学，而RISD学生可以在该校免费选课。
此项安排可扩大课程选择以及课堂讨论的视野，增加学习经验。
该校的美术馆是其最重要的资源之一，收藏了几乎各种文化、时期和类型的艺术与设计精品。
它对学生、学校以及一般民众而言均为伟大的资产，每年吸引近90000参观者。
与RISD就读等于拥有偌大的机会，获得卓越资源、师资和设备的机会。
RISD 欢迎英语为非母语的学生与职员申请入校就学或服务，在入学程序中，要求学生必须参加托福考试，而且笔试分数需要达到580分，或电脑测验分数需达到237分。
我们的国际课程办公室可协助外国学生的申请手续，并答复美国的生活问题，请联络国际课程主任Eva Laporte，邮件信箱：elaporte@，或致电401 454-6725。
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Levels of Polymer Architecture
Monomer Type Molecule Length – molecular weight Mixture of Monomers - copolymers
Types of Copolymers
Homopolymer Random Alternating Block Graft
A polymer is formed by catalyzing the formation of a free radical:
Addition Polymerization
Condensation Reaction
Effects of Polymerization Scheme
Polymer may contain residual byproduct.
Polymer I
Polymerization, Polymer Structure, Morphology
Objectives
1. Explain the basic steps in polymerization.
Objectives
1. Explain the basic steps in polymerization. 2. Explain the epoxy/amine reaction mechanism.
Polymer Categories
Thermoplastic – only secondary bonds between molecules. -”Plastic” or reshapable - Melted and formed under pressure - Higher tooling costs
Addition polymerization done in solvent may have residual solvent
Cleanest polymers are gas phase or aqueous solution polymers
Basic Steps in Polymerization
Objectives
1. Explain the basic steps in polymerization.
2. Explain the epoxy/amine reaction mechanism.
3. Identify the grafting/copolymer structures and/or name them.
Thermoset – primary and secondary bonds between molecule segments. - Cannot be reshaped - Low viscosity in processing - Cheaper tooling
Thermoset
Epoxy Reaction: Primary Amine
Polymer Categories: Network
Thermoset Network Fixed
vs Thermoplastic
Objectives
1. Explain the basic steps in polymerization.
2. Explain the epoxy/amine reaction mechanism.
3. Identify the grafting/copolymer structures and/or name them.
Will share up to four electrons, tetrahedral arrangement
Polymerization Processes
Addition Polymerization
• No Byproducts • Usually heat driven
Condensation Polymerization
Amorphous
Example: Polycarbonate
Crystalline
Example: Polyethylene
Crystals
Chains assume folded chain conformation
These collect into lamellar crystallite
Polypropylene PP
Polystyrene PS
Polyvinylchloride PVC
Levels of Polymer Architecture
Monomer Type Molecule Length
Molecular Weight: Number Average
Weight Average
4. Identify or sketch the various isomeric structures possible with a vinyl polymer.
Objectives
1. Explain the basic steps in polymerization. 2. Explain the epoxy/amine reaction mechanism. 3. Sketch/identify the four basic vinyl molecules 4. Identify the grafting/copolymer structures and/or
name them. 5. Identify or sketch the various isomeric structures
possible with a vinyl polymer. 6. Explain the basis for polymer crystallinity.
Polymer Building Blocks
AAAAAAAAAAA CCACBBACABAA ABCABCABCABC AAAABBBBCCCC
Levels of Polymer Architecture
Monomer Type Molecule Length – molecular weight Mixture of Monomers – copolymers Monomer Arrangement - Isomers
Polymer Categories
Thermoplastic – only secondary bonds between molecules. -”Plastic” or reshapable - Melted and formed under pressure - Higher tooling costs
• Byproducts produced • Removal of byproduct controls rate
Linear Addition
Begin with ethylene (gas) Monomer or “mer” Each bond is a shared electron pair.
Polymer Blends
Mixture of compatible polymers
No primary bonds Intermediate
properties May be phase
separation
Levels of Polymer Architecture
Monomer Type Molecule Length – molecular weight Mixture of Monomers – copolymers Monomer Arrangement – Isomers Bond/Network Structure Molecular Conformation Blends/Alloys Additives
Semicrystalline Thermoplastic
Levels of Polymer Architecture
Monomer Type Molecule Length – molecular weight Mixture of Monomers – copolymers Monomer Arrangement – Isomers Bond/Network Structure Molecular Conformation
Initiation:
Formation of free radical
Propagation:
Combining of mers to form chains
Termination:
Elimination of free radicals
Polymerization Step Effects
The actual method of initiation, propagation, termination will affect final properties.
Isomerism/Polymer Tacticity Isotactic Sindiotactic Random
Levels of Polymer Architecture
Monomer Type Molecule Length – molecular weight Mixture of Monomers – copolymers Monomer Arrangement – Isomers Bond/Network Structure