Synthesis and Properties of Periodic Copolymers

通过适当的聚合物反应合成了交替乙烯-丙烯酸共聚物和交替乙烯-乙烯-丙烯酸共聚物两种周期共聚物，并对其进行了鉴定。所研究的丙烯酸单体有丙烯酸甲酯、甲基丙烯酸甲酯和甲基丙烯腈。并合成了相应的统计共聚物。研究了周期共聚物和统计共聚物的玻璃化转变温度。周期共聚物的玻璃化转变温度与相同组成的统计共聚物相同或几乎相同。在周期性和统计性乙烯-乙烯醇共聚物上也得到了同样的结论。研究了酸性聚合物聚甲基丙烯酸、交替乙烯-甲基丙烯酸共聚物和周期性乙烯-乙烯-甲基丙烯酸共聚物在碱性聚4-乙烯吡啶溶液中的缔合作用。周期共聚物的缔合常数约为其他聚酸的1/100。通过退火和延伸控制周期性乙烯-乙烯-甲基丙烯酸甲酯共聚物的结晶度。获得了结晶度为0 ~ 60%的薄膜样品。给出了试样的应力-应变曲线。

Two types of periodic copolymers, i.e.alternating ethylene-acrylic copolymers and periodic ethylene-ethylene-acrylic copolymers, were synthesized by way of appropriate polymer reactions and identified. Acrylic monomers studied were methyl acrylate, methyl methacrylate, and methacrylonitrile. Corresponding statistical copolymers were also synthesized. The periodic copolymers and the statistical copolymers were studied with respect to their glass transition temperatures. The glass transition temperatures of periodic copolymers were identical or almost the same with those of statistical copolymers of the same composition. The same conclusion was obtained on the periodic and statistical ethylene-vinyl alcohol copolymers. Acidic polymers, i.e.poly(methacrylic acid), alternating ethylene-methacrylic acid copolymer, and periodic ethylene-ethylene-methacrylic acid copolymer were studied on their association in solution with basic poly(4-vinylpyridine). The association constant for the periodic copolymer was ca.1/100 of those of the other polyacids. The crystallinity of periodic ethylene-ethylene-methyl methacrylate copolymer was controlled by annealing and elongation. Film samples of from 0 to 60% crystallinity were obtained. Stress-strain curves of these samples were given.