表面含磺酸基的核-壳型乳胶粒子的制备与表征

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

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％之问。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。

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 polymefized to form a relatively uniform cress-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 convened 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.