Title: ADVANCEMENT OF THE IN-SITU POLYMERIZATION PROCESS FOR GLASS FIBER/NYLON-6 LAMINATES

AbstractThein-situpolymerization process of anionicpolyamide-6 (APA-6) presents the opportunity for a new class of composite materials with excellent performance and wide applicability from automotive, energy, transportation, and aerospace. Despite the inherent advantages with the process, industrial adoption is virtually nonexistent. The following work attempts to advance the APA-6 process in three distinct ways. First, the applicability of graphite-based nanoparticles to improve the processability and final performance of the material was evaluated. Nanographite platelets (NGPs) were selectively incorporated into a woven glass fiber/APA-6 laminate via a spraying technique. The polymerization kinetics were unaffected by the presence of NGPs. Mechanical properties were largely unaffected by NGPs except the matrix-dominated laminate short-beam strength which was increased by 25.6% with a 0.5wt.% NGP concentration. Second, an alternative chemical process enabling a single stream infusion strategy was demonstrated which could greatly improve the automation of the APA-6 process. A soluble diisocyanate initiator (SDI) was synthesized and deposited onto woven glass fabric. A composite laminate was successfully produced using a single, inert solution of monomer and activator. However, an initiator wash-out problem was identified in the process. Surface-initiated polymerization of APA-6 was successfully demonstrated using a specialized silane sizing that contained APA-6 initiation chemistry. Finally, nanographite oxide platelets (NGOPs) were produced using a planetary ball-milling process from graphite flake andcarbon dioxide. A kinetic model was applied to optimize the ball-mill design for simultaneous nanographite exfoliation and carboxylation. The ball-mill was shown to be capable of producing NGOPs with lateral dimensions of