Preparation and properties of glass fiber-reinforced anionic nylon 6 composites by RTM process

Under constant pressure injection condition, glass fiber (GF) reinforced anionic polyamide-6 (APA-6) composites with up to 48vol% fiber contents were successfully manufactured using resin injection molding machine suitable for the reaction system and thermoplastic resin transfer molding (T-RTM) experimental platform which was designed for the process, utilizing the anionic polymerization of caprolactam. The effects of feeding methods, injection pressure, mold temperature and fiber contents on the apparent mass, crystallinity, thermal deformation temperature and mechanical properties of the products were studied. The results show that product with no defect on the surface and excellent performance can be obtained when the injection pressure is 0.5-1.0 MPa under the vacuum pressure with a certain overflow flow. The bending strength and modulus of GF/APA-6 composites reach the highest, 682.7 MPa and 24.4 GPa, respectively when the mold temperature is 150℃. Then, the interlaminar shear strength (ILSS) of composite materials can reach up to 62.3 MPa at 180℃.