关键词: 超高分子量聚乙烯纤维, 石墨烯, Burgers模型, 蠕变, Mori-Tanaka理论, 预测, 复合材料

Abstract: UHMWPE fibers with graphene content ranging from 0% to 15% were prepared via a twin-screw extruder. The creep strain and creep rate of the fibers were measured using constant-load creep tests, and the creep behavior was predicted using the Burgers model. The results showed that as the graphene content increased from 0% to 8%, the fiber’s creep resistance improved. Within the initial 7.5 s of loading, the creep strain ε_7.5 decreased from 2.23% to 1.41%, and the creep rate dε_7.5 dropped from 0.28 s^-1 to 0.19 s^-1. During the stable loading stage, the creep strain ε_{12 000} fell from 7.95% to 3.86%, and the creep rate dε_{12 000} decreased from 3.67×10^-4 s^-1 to 1.83×10^-4 s^-1. However, when the graphene content exceeded 8%, fiber agglomeration reduced the creep resistance. Agglomeration also inhibited the formation of extended-chain crystals of polyethylene macromolecules, causing the peak temperatures of the fiber’s first and second endothermic peaks to decline. The Burgers model could predict the creep behavior of fibers with different graphene contents well, with a mean square error between the predicted and experimental results below 0.06. As the graphene content increased, the model’s elastic modulus (E_M, E_K) and viscosity (η_M, η_K) parameters rose significantly, confirming graphene’s inhibition on polymer chain slippage. As the graphene content increased, the fiber’s elastic modulus rose from 130.3 GPa for pure fibers to 210.3 GPa for fibers with 15% graphene content. When the graphene content exceeded 8%, the experimental values of fiber elastic modulus were lower than the theoretical predictions of the Mori-Tanaka model.

Key words: ultra-high molecular weight polyethylene fiber, graphene, Burgers model, creep, Mori-Tanaka theory, prediction, composites