种子乳液聚合制备可发气P(St/BVA)-PSt核壳微球

Preparation of foamable P(St/BVA)-PSt core-shell microparticles by seeding emulsion polymerization

在种子乳液聚合中加入发泡剂偶氮二甲酰胺(AC),制备可发气P(St/BVA)-PSt核壳微球,并与单纯种子乳液聚合进行了对比,探讨了种子乳液聚合制备核壳结构聚合物粒子的形成机理,分析了可发气微球的形态、结构及热分解特性。结果表明,单纯种子乳液聚合过程生成了新的乳胶粒,包覆AC种子乳液聚合过程未生成新的乳胶粒;前者的反应速率比后者的大;发泡剂AC在180℃加热4～5min出现突发性分解,平衡发气量为175mL/g,可发气微球中的AC分解平缓,平衡发气量为128mL/g。

In the presence of seed emulsion and azodicarbonamide(AC),foamable co re-shell microparticles were prepared by seeding emulsion polymerization and co mpared with normal seeding emulsion polymerization.The preparation mechanism of the core-shell structure microparticles,the morphology and thermal analysis of the decomposition behaviors of the foamable microparticle were studied.The resul ts showed that new latex particles were formed during the normal seeding emulsio n polymerization but that did not happen during the seeding emulsion polymerizat ion folding AC.And polymerization rate of the former was faster than that of the latter.Blowing agent AC decomposed suddenly when it was heated at 180 ℃for 4～ 5 min,and its balance blowing value was 175 mL/g;decomposition of the foamable m icrocellular was more slow,and its balance blowing value was 128 mL/g.