Reaction injection molding (RIM) is a rapid process for producing large light weight plastic parts that are used for automobile and airplane parts among others. Low viscosity liquid reactants (monomers) are mixed and injected into a mold where they reach and form a solid crosslinked polymer product. The two feed streams impinge on each other at high velocity and thus achieve good mixing. Reaction proceeds as bulk copolymerization resulting in segmented block copolyers. The proposed research is aimed at elucidating the fundamental chemistry and physics involved in RIM. The PIs plan to carry out their work in six stages: (1) Model the mold filling and curing steps; (2) Study the chemistry of polyureas and polyurethanes; (3) Look at the role of phase separation during polymerization in the mold; (4) Study the effects of mixing in the mold (5) Obtain morphology measurements; and (6) Study the bubble motion and growth process in RIM due to injected nitrogen gas. The overall goal is to build a model for the RIM process. During the molding cycle the copolymers must grow into long chains and segregate nto hard and soft phases. The work in this project is the analysis of the combination of polymerization kinetics and phase separation dynamics within a flowing mixing, reacting and heat transferring system. The PIs are all very highly thought of and their laboratory is one of the best in the country for this work. The cooperation with industry provides an excellent input to help keep the project aimed in the proper direction. A three year Industry University Cooperative Research Grant is recommended at $154,682 for FY 86, $174,038 for FY 87, and $164,000 for FY 88.
