Pushing the mechanical strength of PolyHIPEs up to the theoretical limit through living radical polymerization

High internal phase emulsion (HIPE) living polymerization was proposed in current work. Reversible addition-fragmentation chain transfer polymerization (RAFT), one of the living radical polymerization methods, was introduced to the polymerization of HIPE for the preparation of polystyrene PolyHIPEs. Living polymerization changed the crosslinking process giving a highly homogeneous polymeric wall of PolyHIPEs. The resolving of the heterogeneity problem increased the mechanical strength of PolyHIPEs significantly with the Young's modulus reaching the theoretical value of similar to 45 MPa, which was more than 3 times higher than that by the conventional method. Not only the open-cellular structure of PolyHIPEs was maintained but also a higher connectivity was achieved. Both the type and the concentration of RAFT agents were found to have influence on the morphology and mechanical strength of PolyHIPEs.