热劣化与测试参数对UHMWPE长丝拉伸性能的影响OA

To investigate the influence of test parameters and thermal degradation on tensile property of ultra-high molecular weight polyethylene(UHMWPE)filaments,the effect rules of gauge length,stretching rate and 80℃thermal degradation treatment on mechanical property of UHMWPE filaments were systematically studied.Tensile tests were carried out by electronic universal test machine with different gauge lengths(5 cm,10 cm and 20 cm)and stretching rates(0.2 mm/min,2 mm/min,10 mm/min and 20 mm/min).Meanwhile,UHMWPE filament was treated for thermal degradation at 80℃for 3 h to 15 h.The results showed when the stretching rate was increased from 0.2 mm/min to 20 mm/min,the breaking strength of UHMWPE filament was increased about 10%,while the change of breaking elongation was not obvious.When the gauge length was increased from 5 cm to 20 cm,the breaking strength of UHMWPE filaments was reduced 1.9%~2.8%due to the"weakest link effect".During thermal degradation,as the thermal degradation treatment time extended,molecular chain orientation and crystallization were decreased,which led to reductions in breaking strength and modulus,while the breaking elongation was increased.After 15 h of thermal degradation,the cumulative breaking strength was decreased by 4.3%,and the breaking elongation was increased by 14.3%.The study provides experimental basis for the engineering application of UHMWPE filaments in high-temperature environments.