十八烷/PSt相变微胶囊的制备及其热性能研究

细乳液法制备了十八烷/聚苯乙烯(PSt)相变微胶囊,用TEM、DLS和DSC等对微胶囊进行了表征。研究了十二烷基硫酸钠(SDS)的加入量、亲水性单体丙烯酸的加入量、引发剂类型以及苯乙烯与十八烷的加料比对产物形态的影响。研究表明:低的SDS浓度有利于微胶囊结构的形成,产物粒子的平均粒径随SDS加入量的增大而减小;加入亲水性共聚单体丙烯酸可以改善微胶囊的形态,但产物中PSt均相微球增多;使用油溶性引发剂AIBN比使用KPS更加有利于微胶囊的形成;苯乙烯与十八烷的投料比为1∶1时,制备的微胶囊相变焓为111.6 J/g。

Preparation and thermal property of octadecane/PSt phase change microcapsules

The phase change microcapsules with octadecane as core and polystyrene as shell were prepared by miniemulsion polymerization.The microcapsules were characterized by TEM,DLS and DSC.The various influences on the colloidal particles including the amount of SDS,the amount of acrylic acid,the type of initiator and the mass ratio of styrene to n-octadecane were studied.The results showed as follows.Low concentration of SDS helped to the formation of microcapsules.The morphology of microcapsules could be improved by using acrylic acid as comonomer.However,it also made for the formation of homogeneous PSt microspheres.Using AIBN as initiator,it was better for the formation of microcapsules than KPS.As the mass ratio of styrene to n-octadecane was 1∶1,the phase change enthalpy of the as-prepared microcapsules was 111.6 J/g.