Crystallinity Effects on Fracture of Rings Made of Thermoplastic Powder Impregnated Carbon or Glass Fiber Composites

Abstract Effects of the supermolecular structure of a thermoplastic matrix on the flexural response of glass (GF) or carbon fiber (CF)/polyamide 12 (PA 12) composite rings were investigated. An additional attempt was made to determine their interlaminar mode I fracture energy. Specimen rings were prepared by dry winding of carbon or glass fibers bundles, interspersed with polyamide powder and surrounded by a polymer sheath, around a metallic core. The consolidation was carried out by a compression molding process. Different morphologies in the polymer matrix of the GF/PA 12 and CF/PA 12 composites were achieved by varying the cooling rate after consolidation of the material in melt and by further thermal treatment. The morphology was studied by DSC and WAXS.