Single polymer laminate composites by compression molding of knitted textiles and microparticles of polyamide 6: Preparation and structure-properties relationship

Knitted reinforced single polymer laminate composites based on polyamide 6 (KSPCsPA6) were produced by compression molding of polyamide 6 microparticles (MPsPA6) powder-coating annealed PA6 Rib or Jersey knitted textile structures. The MPsPA6 were synthesized by solution/precipitation activated anionic ring-opening polymerization of ε-caprolactam. The tensile properties of KSPCsPA6 were studied in relation to the knitted reinforcement architecture, fiber volume fraction, ply orientation and stacking orders. The tensile stiffness and strength of the newly prepared KSPCsPA6 with fiber content of 15% showed significant improvements as compared to the neat anionic PA6 matrix and to commercial hydrolytic PA6 (HPA6). The mechanical behavior of the KSPCsPA6 was correlated with the geometry parameters of the knitted reinforcements, the polymorph content of the samples and their crystallinity indexes determined by differential scanning calorimetry and wide-angle X-ray diffraction. The fracture behavior of KSPCsPA6 was investigated by electron microscopy complemented by simulation studies.