The Control of Attached Acid Groups on Sulfonated Polystyrene Nanospheres through the Design of Material Structure

Abstract

Linearlinking polystyrene nanospheres (LPSs) with uniform size dispersion were synthesized by the emulsifier-free emulsion polymerization method. And with the adding of divinylbenzene (DVB) crosslinking polystyrene nanospheres (CPSs) was also prepared. It was found out that the partical size of prepared nanospheres changed with the continuous increment of added DVB. The sulfonation of resultant polystyrene nanospheres yielded solids with sulfonic acid groups. The relationship between nanospheres material structure and attached acid groups was investigated in detail. It was observed that the amount of added DVB is the main factor which can affect the amount and thermal stability of attached sulfonic acid groups. The catalytic performance of resultant solid acid catalysts was evaluated through the esterification reaction of methanol with acetic acid. Moreover, the prepared sulfonated polystyrene nanospheres show higher acetic acid conversion than the commercial one, therefore the sulfonated nanospheres could be an excellent potential replacement for liquid acid catalyst.