种子聚合法制备PS/PAA核壳微球的研究

设计制备了以疏水性聚苯乙烯(PS)为核、以亲水性聚丙烯酸(PAA)为壳的PS/PAA核壳结构复合微球。首先利用无皂乳液聚合法制备了亚微米级的PS微球,再以其为种子,利用种子无皂乳液聚合法制备PS/PAA核壳微球。在种子聚合阶段,选用AIBN当引发剂,经过红外光谱(IR)表征,表明当使用油溶性引发剂偶氮二异丁腈(AIBN),使其最终形成PS/PAA核壳结构微球。这种方法解决了亲水性较强的单体在以水为介质时在PS微球溶于少量的苯乙烯(St),并在引发聚合之前经过充分的吸附溶胀,可使亲水性单体AAc在PS种子微球表面聚合生成壳层,解决表面不容易直接聚合生成壳层的问题。

Study on Preparation of PS/PAA Core/Shell Composite Particles by Seed Polymerization

The polystyrene/poly(acrylic acid) (PS/PAA) core/shell composite particles with hydrophobic PS as core and hydrophilic PAA as shell were designed and prepared.The PS/PAA particles were synthesized by seeded soap-free emulsion polymerization using submicron-sized PS as seed.During the polymerization,AIBN was used as polymerization initiator.The feasibility of these methods to obtain PS/PAA core/shell particles was discussed in detail.The results show that the core/shell particles can be prepared when employing an oil-soluble initiator,2,2'-azo-bisisobutyr-onitrile (AIBN).This method successfully solves the problem that the hydrophilic monomer is always difficult to polymerize on the surface of hydrophobic PS particles in the water medium.