Development of self-reinforced low-density polyethylene using gamma-irradiation cross-linked polyethylene fibres

摘要

In this study, we investigated low-density polyethylene (LDPE) self-reinforced composites in which the fibres were irradiated with gamma rays prior to compression moulding. The tensile tests of the single fibres revealed that the hot air-assisted melt-spun fibres had better mechanical performance than the same LDPE matrix material. The irradiation cross-linked the fibres, which made it possible to widen the temperature window of the film-stacking method we applied for composite production. The irradiated fibres did not fuse at 120 degrees C, which was above their crystal melting temperature (T-m = 106 degrees C). The effect of irradiation on the mechanical properties of fibres themselves and the composites reinforced with these fibres were investigated. Based on the mechanical and crystalline properties we obtained, the fibres irradiated with an absorbed dose of 200 kGy were chosen as reinforcement for the composites. We performed dynamic mechanical analysis and creep tests on the composites and found that irradiation had a minor effect (10% increase) on storage modulus, while creep strain decreased greatly. The composites with non-irradiated fibres had a creep strain 60% higher at a stress of 2 MPa at the end of the test. LDPE composites with irradiated fibres did not only have improved mechanical performance but they retain the main advantage of self-reinforced composites, which is simple recycling.