多巴胺仿生修饰及聚乙烯亚胺二次功能化表面改性超高分子量聚乙烯纤维

摘要

为提高超高分子量聚乙烯（UHMWPE）纤维与环氧树脂之间的界面剪切强度，采用多巴胺仿生修饰及聚乙烯亚胺（PEI）二次功能化对UHMWPE纤维进行表面改性，并通过FTIR、XPS、SEM和单丝拔出实验等方法分析改性前后UHMWPE纤维的表面特征及UHMWPE/环氧树脂复合材料的界面剪切破坏情况.结果表明：经过多巴胺涂覆和PEI二次功能化后的纤维表面产生羟基和氨基等活性官能团；改性后的纤维表面粗糙度增加；改性前后纤维力学性能基本不变；改性后的UHMWPE纤维与环氧树脂之间的界面剪切强度有所增加，当PEI质量浓度为5 mg/mL时，PEI二次功能化后的UHMWPE纤维与环氧树脂之间的界面剪切强度为1.185 MPa，与未改性UHMWPE纤维复合材料相比，提高了65.27%.%In order to improve the interfacial shear strength of ultra-high molecular weight polyethylene(UHMWPE) fibers and epoxy resin, UHMWPE fibers were modified by bio-dopamine and polyethylene imine (PEI) second functionalization. The surface characteristic of UHMWPE fibers before and after modification and the interfacial shear failure of UHMWPE/epoxy resin composites were analyzed by FTIR, XPS, SEM and single-fiber pull-out test. The results show that the active groups of hydroxyl and amino were introduced into the surface of fibers after dopamine coated and PEI second functionalization. The surface of modified fibers became much rougher. The ex-cellent mechanical property of UHMWPE fibers had no obvious change. The interfacial shear strength of modified fibers and epoxy resin increased. When the concentration of PEI was 5 mg/mL, the interfacial shear strength of the PEI second functionalization UHMWPE fibers and the epoxy resin matrix was 1.185 MPa, and was improved by 65.27%!compared with the pristine UHMWPE fibers composites.