Effect of enhanced γ‐irradiation on the compatibility of polyethylene terephthalate‐based basalt fiber‐reinforced composites

Abstract The interface adhesion between a matrix and fibers is widely known as one of the most important factors affecting the properties of polymer‐based composites. To observe the compatibility of a polymeric matrix and inorganic fibers, polyethylene terephthalate (PET)‐based composites that have been reinforced with various contents of basalt fibers in the presence of a small amount of a polyfunctional monomer, trimethylolpropane triacrylate (TMPTA), were prepared by melt blending and treated via gamma irradiation at various doses. The chemical structure and morphology changes were investigated via gel extraction and scanning electron microscopy, respectively. The mechanical properties and thermal resistance were also studied. The gel fraction results demonstrated that a cross‐linked substance was formed in the composites in the presence of both TMPTA and fibers following irradiation and the maximum gel fraction of PET matrix reached 16 wt%. In addition, the obvious improvement of interfacial adhesion was confirmed by the morphology changes in fracture surface, from which the disappearance of pull‐out holes and plastic deformations of polymeric matrix were observed. As a result of the compatibilization of PET matrix and basalt fibers, both the mechanical strength and the thermal resistance were enhanced, and the optimum amount of TMPTA was 1–3 wt%.