高分子化学(浙江大学) polymer1 Introduction

Mw DP mrepeatingunit
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Polymers are large molecules. Fortunately, they are not random collections of atoms; if this were the case, they would be impossible to study. Polymers are built up from smaller molecules (monomers), and therefore possess a characteristic chain structure consisting of multiple repeat units that are related chemically • The repeat units can all be identical, in which case the compound is a homopolymer(均聚物).
polymer

macromolecule

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1.2 Flowchart of Polymeric Materials
Inorganic • Natural
– Clays • Bricks • Cement • Pottery – Sands • Glass
Organic • Natural – Polysaccharides – Proteins – Polyisoprene • Synthetic – Plastics – Fibers – Rubbers – Adhesive – Coatings – …
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degree of polymerization 聚合度
Note that all three representations are equivalent. One usually chooses the representation that emphasizes the monomer (单体) from which the polymer was made. There are end groups on the chain that are different from the repeat units, but these usually represent a negligible portion of the molecule, so they are seldom drawn.
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Schedule
• • • • Chapter 1 Introduction Chapter 2 Radical Polymerization Chapter 3 Radical Copolymerization Chapter 4 Polymerization Process 3 hr 12 6 3
(Hermann .Staudinger,1924)
Poly comes from the Greek word for "many" and mer comes from the Greek word for "parts“.
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methane
gasoline
wax
polyethylene
carbon
交替 嵌段
无规
接枝
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• The chain itself can have many different topologies
环状 线型 macrocycle 支化
交联 dendrimer 树枝状 27
1.4 Production of polymer
• Nature
– precise control on molecular structure Starch, Natural rubber, Polysaccharides（多糖）
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Polymer(聚合物) vs Macromolecule(大分子)
Macromolecule molecule with high molecule weight molecule comprised of repeating unit
Polymer
Sample
Polyethylene DNA Protein
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• If the repeat units are different, the result is a copolymer(共聚物). Consider a copolymer made from just two ingredients: the two can be sequenced along the backbone in various modes.
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2.1 Classification Rules
• There is no uniform system of classification of polymers. The terminology has evolved along with polymer science, and there are numerous exceptions to categories. • The way people classify polymers depends their experience. • Widely used historical terms or trade names lacking information content.
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• Synthetic
– Fibers
Polymer is everywhere
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In Nature
Cellulose, Starch, DNA, Protein
甲壳素
壳聚糖
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Synthetic Materials
Annual Production of Polymer Materials (million ton) Year Plastics Synthetic fiber Synthetic rubber Total * China 1970 27 4.9 5.5 38 1980 53 12 13 78 1990 107 24 23 154 2000 175(11*) 35 (6.4) 44 (0.9) 254
• Synthetic
– Various families and large quantities, but less precise
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1.5 Polymer Disciplines
Polymer chemistry
Polymer physics
Polymer science
Polymer material
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C: Chemical Composition
• Carbon-chain polymer –backbone composed of carbon atom
C C C C C
• Hetero chain polymer –composed of both carbon and other atoms, e.g. O, N, S, P etc.
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Functional polymers(功能高分子)
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Plastics vs Steel
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Energy Consumption
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Green or not?
Ideal material
polyolefin
paper
glass
aluminium
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1.3. Definitions
CH2CH n Cl
Polymer process
Polymerization engContent
• Polymer and its structure • Polymerization mechanism and kinetics • Polymer reaction
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General Plastics(通用塑料)
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Engineering plastics(工程塑料)
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Synthetic rubber, elastomer (合成橡胶和弹性体)
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Synthetic fibers(合成纤维)
Kevlar Vest
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Fine polymers(精细高分子)
Frontier
• Novel synthetic method and polymer family • Design and control on the chain structure of polymer • Recycle of polymer
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2. Categories and Nomenclature of Polymer
C C O C C O
• Element polymer– no carbon in backbone
• /k/511/
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Chapter I
Introduction
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1. Fundamental Concepts
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1.1 What is a polymer?
A polymer is a large molecule comprised of repeating structural units joined by covalently bonds.
Welcome to
Polymer Chemistry
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Content
• • • • Polymer and its structure Mechanism of polymerization reactions Process of polymerization The reactions of polymer
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Reference Books
• 冯新德，《高分子合成化学》 化学工业出版社，1980。
• 林尚安 等，《高分子化学》科学出版社，2000。
• 赵德仁，张慰盛，《高聚物合成工艺学》化学工业出版社， 1997。
• Malcolm P. Stevens “Polymer Chemistry, an Introduction”, 3rd ed., Oxford University Press, 1999 • George Odian, “Principles of Polymerization”, 2nd ed., John Wiley &Sons, Inc., New York, 1981.
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A: Application
Plastics
Fibers Rubbers Industry Polymer Coatings Adhensives Functional
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General
Fine
B. Processability
结晶
无定形
Molecules in a thermoplastic (热塑性）are held together by relatively weak intermolecular forces, so that the material softens when exposed to heat and then returns to its original condition when cooled A thermosetting(热固性) plastic, or thermoset, solidifies or "sets" irreversibly when heated. Elastomers(弹性体) are rubbery polymers that can be stretched easily to several times their unstretched length and which rapidly return to their original dimensions when the applied stress is released.
O O
NH(CH2)6 NHC(CH2)4C
n
structural unit
结构单元
repeating unit
重复单元
The degree of polymerization (DP) in a polymer molecule is the number, n, of repeating units in the polymer chain.