无皂高分子胶乳粒子的组成、单分散性和稳定性

分别用控压微波辐照法、常压微波辐照法和常压水浴合成法制备出无皂聚苯乙烯胶乳粒子.运用静态激光光散射和动态激光光散射对粒子的表观分子量及其粒径大小与分布进行了表征.结果表明,微波辐照加热法对于形成小尺寸、单分散的胶乳粒子起着很重要的作用.通过凝胶渗透色谱仪（GPC）测定聚合产物的分子量,并结合Zimm作图法,计算出胶乳粒子所含高分子链的数目.发现由控压微波辐照法所得到的聚苯乙烯胶乳粒子的表观分子量最大,而且粒子的分散性并不是由聚合物高分子链的分散性直接决定的.在微波辐照下的无皂乳液聚合,虽然聚合物的高分子链大小不一,但它们在乳液中缠结在一起而形成的胶乳粒子却具有单分散性.通过对均聚和共聚乳液进行静置考察,发现无皂高分子胶乳粒子的稳定性与制备方法、共聚单体的结构及性质有着密切的关系.

The Constitution,Monodispersity and Stability of the Soapless Macromolecule Particles

The soapless polystyrene(PSt )latex particles were prepared by usi ng microwave irradiation in a closed reactor under controlled pre ssure,microw ave irradiation and wa ter bathing under normal pressure,r espec-tively.The a pparent molecular weig ht of the particles and their sizes an d distribution wer e characterized b y using static laser light scattering(SLLS)and dynamic laser light scattering(DLLS).It was found that microwave irra-diation has importa nt effect on the f ormation of the small size and monodi sperse particles.The a verage numbers of the polymer chain in the PSt particle s were calculated by th e combination of gel permeation chromatography(GPC)and Zimm plot.The molecula r weight o f the PSt particles prepared by micro wave irradiation under con-tro lled pressure was bigger than that prepared by other ways.The results showed th at the dispersity of the particles was not determined by the dispersity of the p olymer chain directly.In the soapless emulsion polymerization u nder microwave irradiation,the latex particles composed of the intertwined polymer chain showe d a good monodisp er-sivity,although the polymer chains were not distributed u niformly .In s tudies of the aging of the homopolyme riza-tion and the copolym erization of emu lsion,it was also found that the stab ility of the soapless po lymer partic les has an intimate relationship with the me thod of preparation,t he structure a nd quality of the comonomer.