A NOVEL RESIN DESIGN FOR STYRENIC RESIN - BASED ROOM TEMPERATURE VACUUM INFUSION RESIN TRANSFER MOLDING - SCRIMP

摘要

For low temperature composite manufacturing processes, a major concern for the fabricators is how to design and control the mold filling and curing time. Curing agents like inhibitors or retarders are needed to prevent premature gel and provide a sufficiently long time to complete mold filling. However, the addition of inhibitors or retarders tends to result in a slow mold curing rate and low resin conversion. In this study, a chelating agent, 2,4-pentanedione (2,4-P), is used to manipulate the resin gelation and curing. 2,4-P can interact with promoters (i.e., metal compounds such as cobalt carboxylates) and affect the catalytic activity of the promoter to decompose the initiators, by either retarding or promoting the resin system depending on the initiator and resin system used. It was found that the function of 2,4-P as a retarder or co-promoter for the co-polymerization of styrenic resins depends greatly on the acidity of the resin system used. Based on this observation, a series of SCRIMP molding experiments using a novel resin design was carried out. This design allows 2,4-P to serve as a retarder during mold filling to achieve a long gel time; it then becomes a co-promoter during curing to increase the curing rate and conversion when the acidity of the resin changes.