Copolymérisation anionique du styrène et du divinylbenzène en présence d'une charge polymère. Influence de la masse moléculaire du polystyrène précurseur et de la nature de la charge sur la formation du gel

Polystyrene networks, blended with various polystyrene‐polyisoprene triblock copolymers, were prepared by anionic block copolymerization of styrene and divinylbenzene, the molar masses between crosslinks ranging from 5000 to 60000 g/mol. The influence of the linear polymer upon the formation of the host network was investigated by solvent extraction analysis and swelling experiments. It was found that removal of the soluble polymer out of the gel is completed within ten days of continuous extraction. The initial rate of desorption increases with decreasing the meshes of the network and with increasing the diene content of the block copolymer, i.e. the degree of incompatibility between the polymeric filler and the network. The equilibrium swelling degree of the remaining gels, completely freed of linear chains, was compared to the one of homologous model networks and revealed that the tri‐dimensional structure formed in the presence of a polymer has more defects than the one prepared in pure solvent.