电导滴定研究中空聚合物微球的制备

Conductometric Titration Studying of Hollow Polymer Microspheres Preparation

采用渗透溶胀法制备中空聚合物微球。首先用种子乳液聚合制备了3种不同粒径的酸核S1、S2、S3,然后在酸核上包裹不同质量分数的壳层聚合物,形成一系列核/壳质量比不同的乳胶粒子。通过电导滴定,分析了不同核/壳质量比乳胶粒子表面羧酸的变化,由此来研究壳核包裹过程和确定中空微球形成的最佳核/壳质量比。对不同核/壳质量比的乳胶粒子进行了流变学、遮盖性和TEM分析。实验结果表明,电导滴定所确定的S1、S2、S3形成中空微球的最佳核/壳质量比分别为1/9、1/12、1/9,这与流变学、遮盖性、TEM分析得到的最佳核/壳质量比一致。

Taking osmotic swelling method to prepare hollow polymer microspheres, a series of carboxylated cores S1, S2, S3 were firstly prepared by seeded emulsion polymerization, and then latex particles of different core/shell mass ratios were formed by polymefizing the shell onto the core. The surface carboxyl of the latex particles S1 , S2, S3 with different core/shell mass ratios was determined by conductometric titration, and the change of the surface earboxyl was used to determine the threshold core/shell mass ratio for hollow polymer microsphere. The rheology, the opacifying ability and the TEM of the particles were also studied. The results showed that the best core/shell mass ratios of S1 , S2 and S3 estimated from the conductometric titration are 1/9,1/12 and 1/9 respectively, which, agree well with the rheology, opacifying ability and TEM analyses.