Enhanced interfacial and mechanical property of biodegradable poly(butylene succinate) film via introducing ultrahigh molecular weight polyethylene shish-kebab fibers

Shear-induced ultrahigh molecular weight polyethylene fibers (UFs) with highly oriented shish-kebab structure were achieved from dilute ultrahigh molecular weight polyethylene solution. The ordered UFs were confirmed to have enough strength as reinforced filler to enhance biodegradable poly(butylene succinate) (PBS). PBS/UF composite film was prepared by solution casting and subsequent compression molding. The crystallization behavior, interface and mechanical property of the composite film were studied. Differential scanning calorimetry and x-ray diffraction measurements showed that adding UFs had little effect on the crystallinity and crystal form of PBS. But a remarkable interfacial crystallization behavior around UFs was observed in the composite film due to the unique shish-kebab structure and the relaxation of 'kebab'. Such interfacial crystallization led to a strong interface adhesion between fibers and matrix, and finally enhanced the tensile strength and toughness of PBS. However, the Young's modulus and yield strength of composite film decreased significantly compared to neat PBS, which was related to the break of UFs before yield point. The PBS/UF composite with such a characteristic tensile property has a huge potential for environment-friendly polymer film.