PROPOSED NEW ROUTE FOR IN-MOLD POLYMERIZATION OF STYRENE.

Reaction injection molding (RIM) is experiencing considerable growth due to savings in mold costs for producing large parts. Most of the RIM processes in operation use flexible or semi-rigid polyurethanes. For many structural parts there is a need for more rigid, lower cost materials. Polystyrene, in comparison to most polyurethanes, can provide more rigidity with lower materials costs. Thus, the goal of the described research is to adapt styrene to the RIM process. Data are presented which show that crown ethers can greatly accelerate the rate of anionic polymerization of styrene without causing any loss in molecular weight. With 15-crown-5 present it is possible to convert 93% of the styrene monomer within 10 seconds to polymer with a molecular weight in excess of 30,000 starting at room temperature. considerably more research must be done to characterize this reaction path and demonstrate an in-mold polymerization process.