Vacuum-infused anionic polyamide-6 composites: The effect of postprocessing

Abstract

Research on postprocessing of glass fiber–reinforced anionic polyamide-6 (APA-6) composites was performed in order to optimize the processing time. The two main points of investigation were the cure time and the annealing cycle. It was shown that the optimal mechanical properties (short-beam strength) coincided with the maximum degree of crystallinity for a cure time of 90 min at a cure temperature of 180°C. Annealing close to the crystallization temperature of APA-6 showed the largest increase in degree of crystallinity. For enhanced mechanical properties, however, the processing history is of importance. It was seen that for short cure times, sufficient annealing time at elevated temperatures is beneficial for the polymer chains to branch, cross-link, or adhere to the fibers, hence, significantly improving the mechanical properties.