ABSTRACT

Ultra high molecular weight polyethylenes have been gel-spun into fibers with superior mechanical properties and used as high performance industrial materials. However, their creep property limits their application so far. Ultra high molecular weight ethylene-propylene random copolymers with various methyl branch content were gel-spun and drawn to various extents. Silica-filled epoxy resin has been widely used as a sealing compound for semiconductors. However, the reliability of the semiconductors, especially that of very large scale integrated circuit is strongly affected by the water absorbed in the sealing compound. Numerical simulations which describe various polymer processing operations with a computer aided engineering (CAE) programs have made remarkable advances. Especially CAE has almost made it possible to predict the overall processes in injection molding. However most computer programs available do not involve the detailed crystallization behavior affected by the temperature, shear stress, and pressure to which polymer is subjected.