Interfacial Properties Of Injection Molded Glass Fiber/Thermoplastics Composites

Four kinds of commercial glass fiber reinforced thermoplastics including GF reinforced polypropylene (GF/PP), GF reinforced polyamide 6 (GF/PA6), GF reinforced polycarbonate (GF/PC) and GF reinforced polyoxymethylene (GF/POM) were used in this study. The contents of GF were 10%, 20% and 40%. GF/PP, GF/PA6, PF/PC and GF/POM composites were fabricated to dumbbell specimen by injection molding. The effect of glass fiber contents on tensile properties, morphology and dynamic mechanical properties was investigated. Fiber volume fraction, fiber length distribution and fiber orientation were observed by burning off polymer resin and dispersed remaining fibers on a glass slide. The Kelly Tyson model is used for prediction strength and calculated the critical fiber length of each GF reinforced polymer composites. Tensile strength of all composites increased with increasing glass fiber contents. The fiber orientation factor and the fiber length distribution were increased at higher contents of glass fibers. The interfacial shear strength values of GF/PP, GF/PC and GF/POM composites increased with increasing fiber contents while the declination of the interfacial shear strength was found in GF/PA6 composites. It is interesting to report that the interfacial shear strength of GFRP composites was calulated according to the modified rule of mixture (MROM) and the Kelly-Tyson model, which the interfacial shear strength of the composites increased with incresing glass fiber contents.