热状态下UHMWPE纤维的力学性能

Mechanical properties of UHMWPE fiber under heating state

主要研究热状态下,在一定时间范围内,温度和外力对UHMWPE纤维力学性能的影响。结果表明:随着温度的升高,纤维的强度、断裂伸长、模量以及断裂功都有不同程度的下降。特别是断裂功和强度的下降最为明显,但纤维的断裂伸长随温度的变化不大。用光学显微镜观察到,不同温度下,纤维纵向拉伸断裂处的形态也不同。随着温度的升高,纤维在断裂处不再出现因大分子之间作用力损失而产生的微原纤现象,在拉伸断裂处出现了细颈和微孔。实验表明UHMWPE纤维抗热应力破坏性能很差,温度越高,纤维越容易被破坏。

Mechanical properties of UHMWPE fiber when subjected to heating at different temperatures in a given time （5 seconds） were discussed. The results showed that with the increase of temperature, the strength, breaking elongation, modulus and work of rupture of the fiber are all decreased to a certain extent. Especially the strength and work of rupture decreased sharply, but the breaking elongation only changed slightly. The optical microscope showed that the longitudinal fracture morphology of the fiber when treated at different temperatures were different. With the increasing of temperature, the microfibril which had caused by the weak force of macromolecule remained no more, but the fine cervical and microporous part appeared. This demestrated that the UHMWPE fiber is poor in heat resistance. The higher the temperature, the easier the fiber breaks.