Carbon Fiber-Reinforced Polyamide 6 Composites Formed by In Situ Polymerization—Experimental and Numerical Analysis of the Influence of Polymerization Temperature

Abstract

In this study, carbon fiber-reinforced polyamide 6 composites were prepared by in situ polymerization via vacuum-assisted resin transfer molding (VARTM) in order to evaluate the effect of processing parameters on the mechanical properties and mold filling ratio. At the molding temperature of 140 °C, a high degree of polymerization of the monomer and impregnation of the resin in the preform were empirically observed. The effect of the molding temperature was analyzed by monitoring the mechanical properties (tensile, bending, and impact strength). The mechanical tests showed that the tensile strength, bending strength, bending modulus, and impact strength were highest for the specimens molded at 140 °C compared to those treated at other temperatures. The experimental results were compared with numerical simulations in order to evaluate the relationship between the mold filling ratio and filling time for large-scale automotive parts with various shapes and sizes. The comparison is of great significance for predicting the mold design as well as processing parameters for large-scale automotive parts.

Rapid Impregnating Resins for Fiber-Reinforced Composites Used in the Automobile Industry

“…Generally, the high melting viscosities of thermoplastic polymers require high processing temperatures and pressures to fully impregnate fibers and reduce defects in products [73]. Subsequently, in situ polymerization methods for fiber-reinforced TPCs have been developed using low-viscosity monomers or oligomeric precursors, such as caprolactam [74][75][76][77], laurolactam [78,79], methylmethacrylate (MMA) [80], and cyclic butylene terephthalate (CBT) [81,82], to fabricate fiber-reinforced polyamide 6 (PA6), polyamide 12 (PA12), polymethylmethacrylate (PMMA), and polybutylene terephthalate (PBT) composites, respectively. The global market size for PA 6 is estimated at USD 12.7 billion, and for PA 12, it is estimated at USD 19.43 billion [83].…”