| Abstract: | Unidirectionally reinforced thermoplastic composites of Nylon-6 and polypropylene oxide-Nylon-6 block copolymers have been prepared by the reaction injection molding (RIM)-pultrusion process. This process takes advantage of both the RIM and the pultrusion techniques, while avoiding their inherent shortcomings. It also represents a novel way of incorporating toughening rubber domains into a thermoplastic composite. The composites produced exhibit excellent mechanical integrity with essentially zero void content. The chemical and physical states of the composites produced by the process were probed in terms of mechanical relaxation behavior using a dynamic mechanical spectrometer. Due to the simultaneous occurrence of both polymerization and crystallization processes in the reacting system, the resulting material is in a thermodynamically nonequilibrium state. An annealing effect is shown to correspond structurally to an increase in matrix crystallinity and the degree of phase separation, Izod impact tests were used to compare Nylon-6 and rubber-toughened Nylon-6 RIM-pultruded composites. The potential of secondary processing was, demonstrated by compression molding of the RIM-pultruded composite rods. |
