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1、Chapter 1 Polymeric Fundamental,1:Basic Concepts of Polymer Science P7,The science of macromolecule is divided into: biological and nonbiological materials Polymers, the synthetic materials, refer to: plastics, fibers and elastomers. But nature rubber, wool and cellulose are also included. Polymer c
2、hain can be linear, branched and interconnected The molecular weight of the polymer is the product of the molecular weight of the repeat unit and the degree of polymerization Normally the molecular weight of the polymers are between 10,000 and 1,000,000 The only force between polymer molecules are s
3、econdary bond forces of attraction.,2: Types of polymers P14,Thermoplastics: would soften upon heating, could then be made to flow when a stress was applied, cooled again, would reversibly regain solid or rubbery nature. Thermosets: could be heated to the point where they would soften and be made to
4、 flow under stress once, would not do so reversibly because of a curing reaction. Nature rubber: both, before and after vulcanization. Charles Goodyear in 1839 discovered the curing reaction with sulfur,3: Structure of synthesis P19,The formation condition of linear polymer: difunctional monomer Bra
5、nched polymer: a few points of tri functionality(higher) are introduced at random points along linear chains. Poly(A-g-B) Crosslinked or interconnected or cured polymer: chains are connected in three dimensions by covalent bonds. Appreciation: 理解,欣赏,判断 schematic diagram 示意图，difunctional monomer双官能团单
6、体，a scale model成比例的模型，assume 假设，呈现，承担 Graft copolymer 接枝共聚物 naked eye,Bonding in polymers P21,Types of bonds : primary bonds-covalent bonds; hydrogen bond; van der Waals- dipole interaction; ionicsecondary bonds In linear and branched polymers, secondary bonds hold the individual chains together, ca
7、n flow upon heating-thermoplastics.,4: Polymer Morphology-形态,聚集态结构,高分子链的几何排列P24,An ordered, regular chains are more likely than irregular ones to pack into crystal lattice. Hydrogen bonding and dipole interaction promote crystallinity. Contrast to crystal is amorphous, like cooked spaghetti, or wrig
8、gling snakes Single crystal: folded-chain model-regular reentry model and irregular reentry model/switchboard reentry model. Lamellae thichness: 10nm/0.01um or 50-60 carbon atoms.,Amorphous polymer model,Cooked Spaghetti,Amorphous polymer: Reptation model Crystalline polymer:,Reptation model,5: Tran
9、sitions in polymers P38,The glass transition temperature Tg: Glassy state exists below Tg, rubbery state (橡胶态或高弹态) above Tg. The application T of Plastics is below Tg while that of rubber is above its Tg. Tg, Tm-first-order transition ortransition, motion of segments; Second-order transition or tran
10、sition-blow Tg, motion of chain links, side groups, branched chains,Tanvs. Temperature of Polymer,Chapter 2 Polymeric Materials,Polymer Chemistrypolymer synthesis,step-growth（逐步聚合）chains of any lengths A and B combine to form longer chains-condensation polymerization,?,chain-growth（连锁聚合）-free radica
11、l addition (自由基加成),Three stages of free radical addion polymrization :initiation, propagation, and termination.,Polymerization methods,Emulsion Polymerization: charge: monomer (water insoluble), water, fatty acid soap, water-soluble initiator, chain-transfer agent/ CMC: critical micelle concentratio
12、n（乳液聚合） Ionic polymerization: cationic （悬浮聚合） Bulk Polymerization（本体聚合） Solution polymerization(溶液聚合),The categories of polymeric materials,biological systems such as the human body-proteins, and the like are not discussed,Figure 2 Spectrum of polymeric materials,Natural polymers,Natural rubber from
13、 Hevea trees was being used by the American Indians when Columbus arrived in 1492. Cellulose(纤维素) in different forms, starch(淀粉) and collagen (胶原蛋白)in leather are other examples of natural polymers used.,Many different plastics may be obtained by manipulating_the molecules and changing the chemical
14、_combinations_. Plastics have important roles in agriculture, _application_, clothing, construction, electronics, _furniture_, _packaging_, transportation and numerous other areas. Today we would be utterly _lost_ without the synthetic materials. Plastics have become a part of society which accepts
15、and often _take for granted_the major role of these _fantastic_materials. It might appear that the plastics is a _manufacturing_group unrelated to many other industrial organizations. Many products of other materials _involve_the use of plastics. Metal products are often plastic_coated_. There exist
16、s in the field of plastics, a tremendous shortage of skilled employees and a real need for an expanded program in plastics education at all levels.,Synthetic polymers- Plastics P87,Development of Synthetic polymers P90,2. What is the second synthetic plastic material? What are the typical products? Other name: phenolic resin(酚醛树脂) 3. what led to an overwhelming volume of new plastics? Examples of this type of plastics
