高分子化学（浙江大学） polymer3 Free Radical Copolymerization.pptVIP

* Copolymer composition with conversion Polymerized monomer Monomer before polym. Monomer after polym. Since f varies with conversion, F1 also varies with conversion. Therefore, the average copolymer composition should be obtained by integration * Average copolymer composition M0=1 M St-MMA f10=0.8, f20=0.2, r1=0.53, r2=0.56 F1=f1=0.484 * Controlling copolymer composition 苯乙烯-反丁烯二酸二乙酯共聚物瞬时组成与转化率的关系(r1=0.30, r2=0.07) When the f10 is close to azeotropic point, the copolymer composition slightly varies with conversion (90%). When the f10 is far from azeotropic point, the copolymer composition greatly varies with conversion. By adjusting feed ratio Adding relatively active comonomer during polymerization. * Controlling copolymer composition St-Bd copolymer composition with conversion By controlling monomer conversion Bd-AN copolymer composition with conversion * * * * Chapter 3 Free Radical Copolymerization * 1 Introduction Homopolymerization —— polymerization of one kind of monomer; Copolymerization (addition polymerization) —— polymerization of more than one kind of monomer; 1.1 Concept New kinds of copolymer can be synthesized by copolymerization of different combination of various monomers. Copolymer generated from same monomers can have different compositions and topologies. * Examples Styrene Styrene + Acrylonitrile Styrene + Butadiene Styrene + Acrylonitrile+ Butadiene PS SAN SBR ABS Brittle, transparent, poor solvent toleration High impact, good solvent toleration High elasticity Engineering plastics Maleic anhydride Styrene + maleic anhydride No polymer SMA 1.2 Type of copolymer also obtained by other methods Normally prepared by other methods poly(ethylene-co-propylene) 乙烯-丙烯共聚物 poly(ethylene-r-propylene) 乙烯-丙烯无规共聚物 poly(ethylene-b-propylene) 乙烯-丙烯嵌段共聚物 poly(ethylene-g-propylene) 乙烯-丙烯接枝共聚物 poly(ethylene-a-styrene) 乙烯-苯乙烯交替共聚物 1.2 Nomenclature of copolymer Key topics in copolymerization -ABABBAABABBAAABABA- Composition dist