高分子材料工程专业英语课文翻译9页word
高分子材料工程专业英语翻译
Unit 1 What are polymers?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt.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。
To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands.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。
These big molecules or ‘macro-molecules’ are made up of much sma ller molecules, can be of one or more chemical compounds.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。
To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound.举例说明,想象一组大小相同并由相同的材料制成的环。
高分子材料工程专业英语课文翻译 (2)
高分子材料工程专业英语课文翻译Polymer Science and Polymer Engineering are closely related andoften used interchangeably. Polymer Science is concerned with the chemistry and physics of polymers, while Polymer Engineering teaches students how to design and manufacture polymer products. No matter which field you choose, there is constant innovation and new developments in the field of Polymer Science and Engineering.高分子科学和高分子工程密切相关,常常互换使用。
高分子科学研究聚合物的化学和物理学,而高分子工程则教授学生如何设计和制造聚合物产品。
无论您选择哪个领域,高分子科学和工程的领域中都不断有创新和新发展。
Polymers are large molecules that are made up of repeating units called monomers. These molecules are characterized by their high molecular weight, which gives them unique properties such as strength, elasticity, and durability. There are many types of polymers, including plastics, rubbers, and fibers.聚合物是由称为单体的重复单位组成的大分子。
高分子材料工程专业英语课文翻译
Polymer Materials Engineering Professional EnglishText TranslationIntroductionAs an interdisciplinary field incorporating elements of both chemistry and engineering, Polymer Materials Engineering seeks to synthesize, process, and analyze polymers and polymer-based materialsfor a variety of industrial applications. Materials in this field can range from thermoplastics to thermosets, from elastomers to composites, and from gels to liquid crystals. The study of Polymer Materials Engineering is crucial for industries such as manufacturing, automotive, aerospace, healthcare, and electronics.To master Polymer Materials Engineering, one must not only have a solid foundation in engineering, chemistry, and physics, but also be proficient in technical English. Therefore, reading and translating English texts related to Polymer Materials Engineering is a vital skill for students and professionals in this field.In this article, we will provide a translation of an English text related to Polymer Materials Engineering, with the m of improving readers’ understanding and usage of specialized vocabulary in this field.Text TranslationOriginal English text:Rightly or wrongly, a connection often is made between themechanical performance of a polymeric material and its degree of crystallinity. The inference, however, can be incorrect as many other factors affect the mechanical response of polymer materials. Simply stated, crystalline regions are usually stronger and stiffer than amorphous regions. Generally, the degree of crystallinity that yields optimum properties depends on the polymer type and on the application.Translated text:通常我们会认为高分子材料的力学性能与其结晶度相关联,这种推论并不总是正确的。
高分子材料工程专业英语第二版课文翻译基本全了.doc
A 高分子化学和高分子物理UNIT 1 What are Polymer?第一单元什么是高聚物?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt. To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands. These big molecules or ‘macro-molecules’ are made up of much smaller molecules, can be of one or more chemical compounds. To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound. Alternatively, individual rings could be of different sizes and materials, and interlinked to represent a polymer from molecules of different compounds.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。
高分子材料与工程专业英语翻译
A 高分子化学和高分子物理UNIT 1 What are Polymer?第一单元什么是高聚物?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt. To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands. These big molecules or ‘macro-molecules’are made up of much smaller molecules, can be of one or more chemical compounds. To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound. Alternatively, individual rings could be of different sizes and materials, and interlinked to represent a polymer from molecules of different compounds.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。
高分子材料工程专业英语第二版课文翻译(基本全了
A 高分子化学和高分子物理UNIT 1 What are Polymer?第一单元什么是高聚物?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt. To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands. These big molecules or ‘macro-molecules’ are made up of much smaller molecules, can be of one or more chemical compounds. To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound. Alternatively, individual rings could be of different sizes and materials, and interlinked to represent a polymer from molecules of different compounds.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。
高分子材料工程专业英语第二版课文翻译(基本全了
A 高分子化学和高分子物理UNIT 1 What are Polymer?第一单元什么是高聚物?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt. To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands. These big molecules or ‘macro-molecules’ are made up of much smaller molecules, can be of one or more chemical compounds. To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound. Alternatively, individual rings could be of different sizes and materials, and interlinked to represent a polymer from molecules of different compounds. 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。
(完整word版)高分子材料工程专业英语翻译(word文档良心出品)
Unit 1 What are polymers?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt.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。
To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands.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。
These big molecules or ‘macro-molecules’ are made up of much sma ller molecules, can be of one or more chemical compounds.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。
To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound.举例说明,想象一组大小相同并由相同的材料制成的环。
高分子材料工程专业英语第二版课文翻译(基本全了
A 高分子化学和高分子物理UNIT 1 What are Polymer?第一单元什么是高聚物?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt. To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands. These big molecules or ‘macro-molecules’ are made up of much smaller molecules, can be of one or more chemical compounds. To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound. Alternatively, individual rings could be of different sizes and materials, and interlinked to represent a polymer from molecules of different compounds.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。
高分子材料工程专业英语翻译
Unit 1 What are polymers?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt.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。
To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands.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。
These big molecules or ‘macro-molecules’ are made up of much sma ller molecules, can be of one or more chemical compounds.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。
To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound.举例说明,想象一组大小相同并由相同的材料制成的环。
高分子材料工程专业英语翻译
Unit 1 What are polymers?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt、什么就是高聚物?首先,她们就是合成物与大分子,而且不同于低分子化合物,譬如说普通的盐。
To contrast the difference, the molecular weight of common salt is only 58、5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands、与低分子化合物不同的就是,普通盐的分子量仅仅就是58、5,而高聚物的分子量高于105,甚至大于106。
These big molecules or ‘macro-molecules’ are made up of much smaller molecules, can be of one or more chemical compounds、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,大分子能够就是一种或多种化合物。
To illustrate, imagine that a set of rings has the same size and is made of the same material、When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound、举例说明,想象一组大小相同并由相同的材料制成的环。
【精品】高分子材料工程专业英语词汇及部分课文翻译(可编辑
高分子材料工程专业英语词汇及部分课文翻译------------------------------------------作者------------------------------------------日期专业英语词汇accordion 手风琴 activation 活化(作用)addition polymer 加成聚合物,加聚物 aggravate 加重,恶化 agitation 搅拌 agrochemical 农药,化肥 Alfin catalyst 醇(碱金属)烯催化剂 align 排列成行 aliphatic 脂肪(族)的 alkali metal 碱金属 allyl 烯丙基aluminum alkyl 烷基铝 amidation 酰胺化(作用) amino 氨基,氨基的 amorphous 无定型的,非晶体的 anionic 阴(负)离子的 antioxidant 抗氧剂 antistatic agent 抗静电剂 aromatic 芳香(族)的 arrangement (空间)排布,排列 atactic 无规立构的 attraction 引力,吸引 backbone 主链,骨干 behavior 性能,行为 biological 生物(学)的 biomedical 生物医学的bond dissociation energy 键断裂能 boundary 界限,范围 brittle 脆的,易碎的 butadiene 丁二烯 butyllithium 丁基锂 calendering 压延成型 calendering 压延 carboxyl 羧基 carrier 载体catalyst 催化剂,触媒 categorization 分类(法) category 种类,类型 cation 正[阳]离子cationic 阳(正)离子的 centrifuge 离心 chain reaction 连锁反应 chain termination 链终止 char 炭 characterize 表征成为…的特征 chilled water 冷冻水 chlorine 氯(气) coating 涂覆 cocatalyst 助催化剂 coil 线团 coiling 线团状的 colligative 依数性 colloid 胶体 commence 开始,着手 common salt 食盐 complex 络合物 compliance 柔量 condensation polymer 缩合聚合物,缩聚物conductive material 导电材料 conformation 构象 consistency 稠度,粘稠度 contaminant 污物 contour 外形,轮廓controlled release 控制释放 controversy 争论,争议 conversion 转化率 conversion 转化 copolymer 共聚物 copolymerization 共聚(合) corrosion inhibitor 缓释剂 countercurrent 逆流 crosslinking 交联 crystal 基体,结晶 crystalline 晶体,晶态,结晶的,晶态的crystalline 结晶的 crystallinity 结晶性,结晶度 crystallite 微晶 decomposition 分解 defect 缺陷 deformability 变形性,变形能力 deformation 形变 deformation 变形degree of polymerization 聚合度 dehydrogenate 使脱氢 density 密度depolymerization 解聚 deposit 堆积物,沉积 depropagation 降解 dewater 脱水diacid 二(元)酸 diamine 二(元)胺 dibasic 二元的 dieforming 口模成型 diffraction 衍射 diffuse 扩散 dimension 尺寸 dimensional stability 尺寸稳定性 dimer 二聚物(体) diol 二(元)醇 diolefin 二烯烃 disintegrate 分解,分散,分离 dislocation 错位,位错 dispersant 分散剂 dissociate 离解 dissolution 溶解dissolve 使…溶解distort 使…变形,扭曲 double bond 双键dough (生)面团,揉好的面 drug 药品,药物elastic modulus 弹性模量 elastomer 弹性体 eliminate 消除,打开,除去 elongation 伸长率,延伸率 entanglement 缠结,纠缠 entropy 熵 equilibrium 平衡 esterification 酯化(作用) evacuate 撤出 extrusion 注射成型 extrusion 挤出 fiber 纤维flame retardant 阻燃剂 flexible 柔软的flocculating agent 絮凝剂folded-chain lamella theory 折叠链片晶理论 formulation 配方 fractionation 分级 fragment 碎屑,碎片 fringed-micelle theory 缨状微束理论 functional group 官能团 functional polymer 功能聚合物 functionalized polymer 功能聚合物 gel 凝胶glass transition temperature 玻璃化温度 glassy 玻璃(态)的 glassy 玻璃态的 glassy state 玻璃态 globule 小球,液滴,颗粒 growing chain 生长链,活性链 gyration 旋转,回旋 hardness 硬度 heat transfer 热传递 heterogeneous 不均匀的,非均匀的 hydocy acid 羧基酸 hydrogen 氢(气) hydrogen bonding 氢键 hydrostatic 流体静力学 hydroxyl 烃基 hypothetical 假定的,理想的,有前提的 ideal 理想的,概念的 imagine 想象,推测imbed 嵌入,埋入,包埋 imperfect 不完全的 improve 增进,改善 impurity 杂质 indispensable 不了或缺的 infrared spectroscopy 红外光谱法 ingredient 成分 initiation (链)引发 initiator 引发剂inorganic polymer 无机聚合物 interaction 相互作用 interchain 链间的interlink 把…相互连接起来连接 intermittent 间歇式的 intermolecular (作用于)分子间的 intrinsic 固有的 ion 离子ion exchange resin 离子交换树脂 ionic 离子的 ionic polymerization 离子型聚合 irradiation 照射,辐射 irregularity 不规则性,不均匀的 isobutylene 异丁烯 isocyanate 异氰酸酯 isopropylate 异丙醇金属,异丙氧化金属isotactic 等规立构的 isotropic 各项同性的 kinetic chain length 动力学链长 kinetics 动力学 latent 潜在的light scattering 光散射 line 衬里,贴面 liquid crystal 液晶macromelecule 大分子,高分子 matrix 基体,母体,基质,矩阵 mean-aquare end-to-end distance 均方末端距mechanical property 力学性能,机械性能mechanism 机理medium 介质中等的,中间的 minimise 最小化 minimum 最小值,最小的 mo(u)lding 模型 mobility 流动性 mobilize 运动,流动 model 模型 modify 改性molecular weight 分子量 molecular weight distribution 分子量分布molten 熔化的monofunctional 单官能度的 monomer 单体 morphology 形态(学) moulding 模塑成型 neutral 中性的 nonelastic 非弹性的nuclear magnetic resonance 核磁共振 nuclear track detector 核径迹探测器 number average molecular weight 数均分子量occluded 夹杂(带)的 olefinic 烯烃的optimum 最佳的,最佳值[点,状态] orient 定向,取向 orientation 定向 oxonium 氧鎓羊 packing 堆砌 parameter 参数 parison 型柸pattern 花纹,图样式样 peculiarity 特性 pendant group 侧基 performance 性能,特征 permeability 渗透性pharmaceutical 药品,药物,药物的,医药的phenyl sodium 苯基钠 phenyllithium 苯基锂 phosgene 光气,碳酰氯 photosensitizer 光敏剂 plastics 塑料 platelet 片晶 polyamide 聚酰胺 polybutene 聚丁烯polycondensation 缩(合)聚(合) polydisperse 多分散的 polydispersity 多分散性polyesterification 聚酯化(作用) polyethylene 聚乙烯 polyfunctional 多官能度的 polymer 聚合物【体】,高聚物 polymeric 聚合(物)的 polypropylene 聚苯烯 polystyrene 聚苯乙烯 polyvinyl alcohol 聚乙烯醇 polyvinylchloride 聚氯乙烯 porosity 多孔性,孔隙率 positive 正的,阳(性)的 powdery 粉状的 processing 加工,成型 purity 纯度 pyrolysis 热解 radical 自由基radical polymerization 自由基聚合 radius 半径 random coil 无规线团 random decomposition 无规降解 reactent 反应物,试剂reactive 反应性的,活性的 reactivity 反应性,活性 reactivity ratio 竞聚率 real 真是的 release 解除,松开 repeating unit 重复单元 retract 收缩 rubber 橡胶 rubbery 橡胶态的 rupture 断裂 saturation 饱和 scalp 筛子,筛分 seal 密封secondary shaping operation 二次成型 sedimentation 沉降(法) segment 链段 segment 链段semicrystalline 半晶 settle 沉淀,澄清 shaping 成型 side reaction 副作用 simultaneously 同时,同步 single bond 单键 slastic parameter 弹性指数 slurry 淤浆 solar energy 太阳能 solubility 溶解度 solvent 溶剂 spacer group 隔离基团 sprinkle 喷洒 squeeze 挤压srereoregularity 立构规整性【度】 stability 稳定性 stabilizer 稳定剂 statistical 统计的step-growth polymerization 逐步聚合 stereoregular 有规立构的,立构规整性的stoichiometric 当量的,化学计算量的 strength 强度stretch 拉直,拉长 stripping tower 脱单塔 subdivide 细分区分 substitution 取代,代替 surfactant 表面活性剂 swell 溶胀 swollen 溶胀的 synthesis 合成 synthesize 合成 synthetic 合成的tacky (表面)发粘的 ,粘连性 tanker 油轮,槽车tensile strength 抗张强度 terminate (链)终止tertiary 三元的,叔(特)的tetrahydrofuran 四氢呋喃 texture 结构,组织 thermoforming 热成型 thermondynamically 热力学地 thermoplastic 热塑性的 thermoset 热固性的three-dimensionally ordered 三维有序的 titanium tetrachloride 四氯化钛 titanium trichloride 三氯化铁 torsion 转矩transfer (链)转移,(热)传递 triethyloxonium-borofluoride 三乙基硼氟酸羊trimer 三聚物(体)triphenylenthyl potassium 三苯甲基钾 ultracentrifugation 超速离心(分离) ultrasonic 超声波 uncross-linked 非交联的 uniaxial 单轴的 unsaturated 不饱和的 unzippering 开链 urethane 氨基甲酸酯 variation 变化,改变 vinyl 乙烯基(的) vinyl chloride 氯乙烯 vinyl ether 乙烯基醚 viscoelastic 黏弹性的 viscoelastic state 黏弹态 viscofluid state 黏流态 viscosity 黏度viscosity average molecular weight 黏均分子量viscous 粘稠的 vulcanization 硫化weight average molecular weight 重均分子量X-ray x射线 x光 yield 产率Young's modulus 杨氏模量课文翻译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。
高分子材料工程专业英语第二版课文翻译(基本全了
仅供个人参考ForpesnauseonysudyandresachnofrcmmercauseA 高分子化学和高分子物理蚆UNIT 1 What are Polymer? 节什么是高聚物?第一单元袁What are polymers? For one thing, they are complex and giant molecules and are 蝿contrast To common salt. weight compounds like, say, different from low molecularthe difference, the molecular weight of common salt is only 58.5, while that ofa polymer can be as high as several hundred thousand, even more than thousand smaller of much ' are made up These thousands. big molecules or‘macro-moleculesmolecules, can be of one or more chemical compounds. To illustrate, imagine thatthings When these the same material. the same size and is made of of a set rings has from polymer as representing a the chain formed can be considered are interlinked, of be rings could same of the compound. Alternatively, individual moleculesfrom a represent polymer materials, and interlinked to different sizes and molecules of different compounds.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,譬如说普通蒇,而高聚物的分子量高于的盐。
高分子材料工程专业英语翻译
Unit 1 What are polymers?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt.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。
To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands.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。
These big molecules or ‘macro-molecules’ are made up of much sma ller molecules, can be of one or more chemical compounds.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。
To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound.举例说明,想象一组大小相同并由相同的材料制成的环。
高分子材料工程专业英语翻译
Unit 1 What are polymers?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt.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。
To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands.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。
These big molecules or ‘macro-molecules’ are made up of much sma ller molecules, can be of one or more chemical compounds.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。
To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound.举例说明,想象一组大小相同并由相同的材料制成的环。
高分子材料工程专业英语翻译
Unit 1 What are polymers?What are polymers? For one thing, they are complex and giant molecules and are different from low molecular weight compounds like, say, common salt.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。
To contrast the difference, the molecular weight of common salt is only 58.5, while that of a polymer can be as high as several hundred thousand, even more than thousand thousands.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。
These big molecules or ‘macro-molecules’ are made up of much sma ller molecules, can be of one or more chemical compounds.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。
To illustrate, imagine that a set of rings has the same size and is made of the same material. When these things are interlinked, the chain formed can be considered as representing a polymer from molecules of the same compound.举例说明,想象一组大小相同并由相同的材料制成的环。
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A高分子化学和高分子物理UNIT 1 What ar e Polym er?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。
盐,代表一种低分子量化合物,在水中达到点(叫饱和点)溶解,但,此后,进一步添加盐不进入溶液中却沉到底部而保持原有的固体状态。
饱和盐溶液的粘度与水的粘度不是十分不同,但是,如果我们用聚合物替代,譬如说,将聚乙烯醇添加到固定量的水中,聚合物不是马上进入到溶液中。
聚乙烯醇颗粒首先吸水溶胀,发生形变,经过很长的时间以后进入到溶液中。
同样地,我们可以将大量的聚合物加入到同样量的水中,不存在饱和点。
将越来越多的聚合物加入水中,认为聚合物溶解的时间明显地增加,最终呈现柔软像面团一样粘稠的混合物。
另一个特点是,在水中聚乙烯醇不会像过量的氯化钠在饱和盐溶液中那样能保持其初始的粉末状态。
总之,我们可以讲(1)聚乙烯醇的溶解需要很长时间,(2)不存在饱和点,(3)粘度的增加是典型聚合物溶于溶液中的特性,这些特性主要归因于聚合物大分子的尺寸。
如图1.2说明了低分子量化合物和聚合物的溶解行为。
氯化钠晶体加入到水中——→晶体进入到溶液中.溶液的粘度不是十分不同于充分搅拌水的粘度——→形成饱和溶液.剩余的晶体维持不溶解状态.加入更多的晶体并搅拌氯化钠的溶解聚乙烯醇碎片加入到水中——→碎片开始溶胀——→碎片慢慢地进入到溶液中允许维持现状充分搅拌——→形成粘稠的聚合物溶液.溶液粘度十分高于水的粘度继续搅拌聚合物的溶解图1.2 低分子量化合物(氯化钠)和聚合物(聚乙烯醇)不同的溶解行为UNIT 2 Chain Polymerization第二单元链式聚合反应Staudinger第一个发现一例现象,许多烯烃和不饱和烯烃通过打开双键可以形成链式大分子。
二烯烃以同样的方式聚合,然而,仅限于两个双键中的一个。
这类反应是通过单体分子首先加成到引发剂自由基或引发剂离子上而进行的,靠这些反应活性中心由引发剂转移到被加成的单体上。
以同样的方式,借助于链式反应,单体分子一个接一个地被加成(每秒2000~20000个单体)直到活性中心通过不同的反应类型而终止。
聚合反应是链式反应的原因有两种:因为反应动力学和因为作为反应产物它是一种链式分子。
链分子的长度与动力学链长成正比。
链式反应可以概括为以下过程(R·相当与引发剂自由基):略因而通过上述过程由氯乙烯得到聚氯乙烯,或由苯乙烯获得聚苯乙烯,或乙烯获得聚乙烯,等等。
借助于聚合度估算的分子链长,在一个大范围内可以通过选择适宜的反应条件被改变。
通常,通过大量地制备和利用聚合物,聚合度在1000~5000范围内,但在许多情况下可低于500、高于10000。
这不应该把所有聚合物材料的分子量理解为由500,或1000,或5000个单体单元组成。
在几乎所有的事例中,聚合物材料由不同聚合度的聚合物分子的混合物组成。
聚合反应,链式反应,依照与众所周知的氯(气)-氢(气)反应和光气的分解机理进行。
双键活化过程的引发剂反应,可以通过热、辐射、超声波或引发剂产生。
用自由基型或离子型引发剂引发链式反应可以很清楚地进行观察。
这些是高能态的化合物,它们能够加成不饱和化合物(单体)并保持自由基或离子活性中心以致单体可以以同样的方式进一步加成。
对于增长反应的各个步骤,每一步仅需要相当少的活化能,因此通过一步简单的活化反应(即引发反应)即可将许多烯类单体分子转化成聚合物,这正如连锁反应这个术语的内涵那样。
因为少量的引发剂引发形成大量的聚合物原料(1:1000~1:10000),从表面上看聚合反应很可能是催化反应。
由于这个原因,通常把聚合反应的引发剂看作是聚合反应的引发剂,但是,严格地讲它们不是真正意义上的催化剂,因为聚合反应的催化剂进入到反应内部而成为一部分,同时可以在反应产物,既聚合物的末端发现。
此外离子引发剂和自由基引发剂有的是金属络合物引发剂(例如,通过四氯化钛或三氯化钛与烷基铝的反应可以得到),Z引发剂在聚合反应中起到了重要作用,它们催化活动的机理还不是十分清楚。
UNIT 3 Step-Growth Polymerization第三单元逐步聚合许多不同的化学反应通过逐步聚合可用于合成聚合材料。
这些反应包括酯化、酰胺化、氨基甲酸酯、芳香族取代物的形成等。
通过反应聚合反应在两种不同的官能团,如,羟基和羧基,或异氰酸酯和羟基之间。
所有的逐步聚合反应根据所使用单体的类型可分为两类。
第一类涉及两种不同的官能团单体,每一种单体仅具有一种官能团。
一种多官能团单体每个分子有两个或多个官能团。
第二类涉及含有两类官能团的单种单体。
聚酰胺的合成说明了聚合反应的两个官能团。
因此聚酰胺可以由二元胺和二元酸的反应或氨基酸之间的反应得到。
nH2N-R-NH2+nHO2C-R’-CO2H→H-(-NH-R-NHCO-R’-CO-)n-OH+(2n-1)H2O (3.1)or from the reaction of amino acids with themselvesnH2R-CO2H→H-(-NH-R-CO-)n-OH+(n-1)H20 (3.2)The two groups of reactions can be represented in a general manner by the equations as followsA+B-B →–[-A-A-B-B-]-A-B→–[-A-B-]-两种官能团之间的反应一般来说可以通过下列反应式表示反应式略反应(3.1)说明前一种形式,而反应(3.2)具有后一种形式。
图3.1 逐步聚合的示意图(a)未反应单体;(b)50%已反应;(c)83.3%已反应;(d) 100%已反应(虚线表示反应种类)聚酯化,是否在二元酸和二元醇或羟基酸分子间进行,是逐步聚合反应过程的一个例子。
酯化反应出现在单体本体中两个单体分子相碰撞的位置,且酯一旦形成,依靠酯上仍有活性的羟基或羧基还可以进一步进行反应。
酯化的结果是单体分子很快地被消耗掉,而分子量却没有多少增加。
图3.1说明了这个现象。
例如,假定图3.1中的每一个方格代表一个羟基酸分子。
(b)中的二聚体分子,消耗二分之一的单体分子聚合物种类的聚合度(DP)是2。
(c)中当三聚体和更多的二聚体形成,大于80%的单体分子已反应,但DP仅仅还是2.5。
(d)中当所有的单体反应完,DP是4。
但形成的每一种聚合物分子还有反应活性的端基;因此,聚合反应将以逐步的方式继续进行,其每一步酯化反应的反应速率和反应机理均与初始单体的酯化作用相同。
因此,分子量缓慢增加直至高水平的单体转化率,而且分子量将继续增加直到粘度的增加使其难以除去酯化反应的水或难以找到相互反应的端基。
在A-A+B-B的聚合反应中也可以看到,精确的当量平衡是获得高分子量所必需的。
假如存在一些但官能团杂质,由于链的端基失活,反应将使分子量减少。
同样,在A-B类的缩聚反应中高纯度的单体是必要的,而且可以归结高收率的反应仅是形成聚合物的实际反应,因为副反应会破坏当量平衡。
第四单元离子聚合反应离子聚合反应,与自由基聚合反应相似,也有链反应的机理。
但是,离子聚合的动力学明显地不同于自由基聚合反应。
(1)离子聚合的引发反应仅需要很小的活化能。
因此,聚合反应的速率仅对温度有较少的依赖性。
在许多情况下离子聚合猛烈地发生甚至低于50℃(例如,苯乙烯的阴离子聚合反应在-70℃在四氢呋喃中,或异丁烯的阳离子聚合在-100℃在液态乙烯中)。
(2)对于离子聚合来说,不存在通过再结合反应而进行的强迫链终止,因为生长链之间不能发生链终止。
链终止反应仅仅通过杂质而发生,或者说通过和某些像水、醇、酸、胺或氧这样的化合物进行加成而发生,且一般来说(链终止反应)可通过这样的化合物来进行,这种化合物在中性聚合物或没有聚合活性的离子型聚合物生成的过程中可以和活性聚合物离子进行反应。
如果引发剂仅仅部分地离解,引发反应即为一个平衡反应,在出现平衡反应的场合,在一个方向上进行链引发反应,而在另一个方向上则发生链终止反应。
通常离子聚合反应能通过酸性或碱性化合物被引发。
对于阳离子聚合反应来说,BF3,AlCl3,TiCl4和SnCl4与水、或乙醇,或叔烊盐的络合物提供了部分活性。
正离子是产生链引发的化合物。
例如:(反应略)三乙基硼氟酸烊然而,BF3也可以与HCl、H2SO4和KHSO4引发阳离子聚合反应。
阴离子聚合反应的引发剂是碱金属和它们的有机金属化合物,例如苯基锂、丁基锂和三苯甲基锂,它们在不同的溶剂中或多或少地强烈分解。
所谓的Alfin催化剂就是属于这一类,这类催化剂是异丙醇钠、烯丙基钠和氯化钠的混合物。
BF3为引发剂(异丁烯为单体),证明仅在痕量水或乙醇的存在下聚合反应是可以进行的。
如果消除痕量的水,单纯的BF3不会引发聚合反应。