表面含磺酸基的核-壳型乳胶粒子的制备与表征

为了合成表面含磺酸基的双亲型核-壳聚合物,本文采用两步乳液聚合法,第1步合成PS种子乳液;第2步用氧化还原引发体系在PS种子乳胶粒外包覆1层交联的聚苯乙烯磺酸酯,得到表面含磺酸酯的核-壳型聚苯乙烯(CPS)乳胶粒子。通过调节壳层单体的加入量,可以控制外壳层聚合物的质量分数(相对核层)在10%~30%之间。将外壳层的磺酸酯基水解转化成磺酸基得目标产物。用透射电子显微镜(TEM)、红外光谱(IR)、差热分析(DSC)和热失重分析(TGA)、X射线光电能谱(XPS)等方法对制备的乳胶粒子进行了测试和表征。

Synthesis and Characterization of Core-Shell Particles Bearing Sulfuric Acid Groups on the Surface

Described in this work is the preparation and characterization of a kind of core-shell particles with a hydrophobic PS core and a hydrophilic shell with sulfonic groups.First,a polystyrene(PS) latex was prepared by conventional emulsion polymerization.Subsequently,by using the PS latex as seed,a mixture of butyl 4-vinylbenzenesulfonate and divinylbenzene was added and polymerized to form a relatively uniform cross-linking shell surrounding the PS core under the effect of a redox initiation system at ambient temperature.The content of the shell ranged from 10～30 wt% relative to that of the core.Finally,the sulfonate groups existing in the shell were converted into sulfuric acids through hydrolysis at elevated temperature,resulting in a charged hydrophilic shell.The structure,composition and size of the latex particles were fully characterized by transmission electron microscopy(TEM),infrared spectra(IR),differential thermal analysis(DSC) and X-ray photoelectron spectroscopy(XPS).Colloidal particles were obtained from the emulsion by precipitation in stirred methanol solution,filtration and washing with cold water.The solid particles exhibited self-emulsifying ability and could be redispersed in deionized water and the latex dispersion remained stable as long as we observed.