A thermoplastic pultrusion was carried out to prepare the long fibre reinforced thermoplastic (LFT) composites based on polyoxymethylene(POM) matrix on the custom-designed pultrusion equipment. The investigation on mechanical performance revealed that the POM-based LFT composites achieved much higher tensile, flexural, and impact strength than the short glass fibre reinforced ones at the same fibre loadings. Such a promising reinforcement effect was attributed to the feature that the residual fibre length in the injection-molded LFT products was greatly superior to that in short fibre reinforced ones. This takes full advantage of the strength of the reinforcing fibre itself.The scanning electronic microscopy demonstrated that the fiber fracture and fiber pull-out concurred on the tensile and impact fracture surfaces, and the former preceded the latter. The crystallization kinetics of the POM-based LFT composites were also in-depth studied in terms of the nonisothermal and isothermal crystallization processes. The kinetic investigation indicated that the crystallinity of POM domain was enhanced by the heterogeneous nucleation of glass fibre, but the crystallization rate was postponed due to the interspace restriction toward crystalline growth caused by long glass fibre. These kinetic parameters provided information on the processing conditions of POM-based LFT composites for the injection- and compression-molding. The thermal stability of the POM composites was also improved in the presence of long glass fibre. It is prospective that the development of POM-based LFT composites will provide opportunities for the expanded applications of thermoplastic composites with POM matrix.
