N⁃苯基马来酰亚胺共聚物的合成及对PVC树脂耐热改性效果研究

Synthesis of N⁃phenylmaleimide copolymer and its heat⁃resistant modification effect on PVC resin

通过种子乳液聚合结合半连续加料方式,成功聚合出分子结构一致且与聚氯乙烯(PVC)树脂具有良好相容性的聚(N‐苯基马来酰亚胺‐苯乙烯‐丙烯腈)(PNSA)共聚物胶乳,将其与PVC树脂直接复合制备PNSA/PVC复合材料,并对PNAS耐热改性的效果进行评价。结果表明,PNSA纳米胶乳颗粒粒径在155.3~251.5 nm之间,粒径分布均一;PNSA共聚物分子组成呈无规结构,分子结构一致,差示扫描量热曲线呈现单一的玻璃化转变温度(T_(g)),且与PVC树脂具有极佳的相容性;PNSA含量由0升高至50%(质量比,下同)时,复合材料的T_(g)由84.8℃提高到107.2℃,提高了22.4℃,维卡软化温度由71.2℃提高到91.9℃,提高了20.7℃;除耐热性改善以外,复合材料的力学性能也有一定程度的提高,本文的研究有利于PVC应用领域的进一步拓展。

A poly(N‐phenylmaleimide-styrene-acrylonitrile)copolymer(PNSA)latex with a uniform molecular structure and good compatibility with PVC was successfully prepared through seed emulsion polymerization combined with a semicontinuous feeding method.PNSA/PVC blends were prepared through directly compounding PNSA with PVC resin,and its heat‐resistant modification effect was evaluated.The results indicated that the PNSA latex exhibited a random structure and a uniform particle‐size distribution ranging from 155.6 to 249.3 nm.The molecular structure of PNSA is uniform.The differential scanning calorimetry curve shows a single glass transition temperature(T_(g))for PNSA,suggesting its excellent compatibility with PVC resin.When the addition amount of PNSA was increased from 0 to 50 wt%,the blends presented an increase in T_(g)from 84.8 to 107.2℃,and their Vicat softening temperature increased from 71.2 to 91.9℃.In addition to heat‐resistant modification,the mechanical properties of the blends were also improved to a certain extent.This study is conducive to further expanding the application field of PVC.