Comparison of unsaturated polyester and vinylester resins in low temperature polymerization

Many composite products are produced at low temperatures in processes such as resin transfer molding (RTM)I vacuum infusion molding (e.g., Seemann Com posite Resin Infusion Molding Process-SCRIMP), and hand lay-up. These proce sses are widely used far marine, civil infrastructure, transportation and d efense applications. Unsaturated polyester and vinylester resins are two ma jor resins used in these processes due to their low cost, good performance, and processibility. Ln this study, the reaction kinetics and rheological c hanges of these two resins cured at low temperatures were studied. Effects of resin type, initiator, promoter, inhibitor and retarder on the reaction kinetics and rheological behaviors were examined using a Differential Scann ing Calorimeter (DSC) and a Rheometrics Dynamic Analyzer (RDA). A model was developed to quantify the effects of resin type, temperature, and differen t curing agents on the gel time for both polyester and vinylester resins cu red at low temperatures. (C) 2000 John Wiley & Sons, Inc.