不同改性方法对超高分子量聚乙烯纤维蠕变行为的影响  

Impact of different modification methods on creep behavior of ultra-high molecular weight polyethylene fibers

作　　者：郑晗 孙勇飞 王新威 ZHENG Han;SUN Yongfei;WANG Xinwei(Shanghai Research Institute of Chemical Industry Co.,Ltd.,Shanghai 200062,China;State Key Laboratory of Polyolefins and Catalysis,Shanghai 200062,China)

机构地区：[1]上海化工研究院有限公司,上海200062 [2]聚烯烃催化技术与高性能材料国家重点实验室,上海200062

出　　处：《工程塑料应用》2024年第8期140-147,共8页Engineering Plastics Application

基　　金：上海市青年科技启明星计划资助项目(21QB1402600)。

摘　　要：超高分子量聚乙烯(PE-UHMW)纤维因其优异的性能广泛应用于多个领域,但其在长时间负载下易蠕变的问题限制了其更广泛的应用。关于PE-UHMW纤维的研究多关注于纤维本身的蠕变性能优化,对蠕变过程和蠕变行为讨论较少。通过石墨烯共混改性和支化改性两种方法制备得到了不同性能的耐蠕变纤维样品,通过力学性能表征、40%断裂载荷下3 h的蠕变测试和差示扫描量热(DSC)测试,探讨了不同纤维的蠕变行为和对应的蠕变机理。实验对比了常规纤维、掺杂不同含量石墨烯的PE-UHMW纤维以及不同支化度的PE-UHMW纤维和商业耐蠕变纤维Dyneema DM20纤维,研究发现,共混改性和支化改性均能提高PE-UHMW纤维的耐蠕变性能,但表现出不同的蠕变行为和机理。石墨烯的添加能够有效降低PE-UHMW纤维的初始蠕变量,尤其是在石墨烯质量分数为8%时,纤维的蠕变变形减少了37.6%,当石墨烯质量分数大于8%后,初始蠕变量反而增加;支化改性对纤维蠕变性能的影响主要体现在恒定载荷下的抗形变能力。包含支链的纤维初始蠕变量要大于未改性纤维,但其在第二阶段的蠕变速率显著降低,显示出更好的耐蠕变性能。通过对蠕变曲线进行时间外推验证了改性纤维在长期载荷下的稳定性。石墨烯共混改性使纤维的DSC吸热峰值升高至146℃以上,支化改性纤维则展现3个独立吸热峰,表明支链引入新的微观结构。最后讨论分析了不同改性方法对PE-UHMW纤维蠕变行为的影响机制。Ultra-high molecular weight polyethylene(PE-UHMW)fibers are widely used in various fields due to their excellent properties.However,their tendency to creep under long-term load limits their broader applications.Most research on PEUHMW fibers focuses on optimizing the creep performance of the fibers themselves,with less discussion on the creep process and behavior.Creep-resistant fiber samples with different properties through two modification methods were prepared:graphene blending and branching modification.The creep behavior and corresponding mechanisms of different fibers were investigated through mechanical performance characterization,a 3-hour creep test at 40%of the breaking load,and differential scanning calorimetry(DSC)testing.Conventional fibers,PE-UHMW fibers doped with varying amounts of graphene,PE-UHMW fibers with different degrees of branching,and commercial creep-resistant fibers Dyneema DM20 were compared.It was found that both blending and branching modifications could enhance the creep resistance of PE-UHMW fibers,but they exhibit different creep behaviors and mechanisms.The addition of graphene effectively reduce the initial creep deformation of PE-UHMW fibers,particularly at a graphene content of 8%,where the creep deformation decreased by approximately 30%.However,when the graphene content exceed 8%,the initial creep deformation increase instead.The impact of branching modification on fiber creep performance mainly manifest in improving deformation resistance under constant load.Fibers with branches has a greater initial creep deformation than unmodified fibers,but their second-stage creep rate significantly decrease,showing better creep resistance.Time extrapolation of the creep curves verify the stability of modified fibers under long-term load.Graphene blending modification increase DSC endothermic peak of the fibers to above 146℃,while branched fibers exhibite three distinct endothermic peaks,indicating that branches introduce new microstructures.Finally,the mechanisms by which differen

关 键 词：超高分子量聚乙烯纤维 蠕变行为 共混改性 支化改性 分子链滑移 石墨烯 

分 类 号：TQ342.6[化学工程—化纤工业]