邻苯二酚-四乙烯五胺改性超高分子量聚乙烯纤维

应用Cat-TEPA改性超高分子量聚乙烯(UHMWPE)纤维,在难黏附的纤维表面形成均匀涂层.采用透射电子显微镜(TEM)、红外光谱(FTIR)、X射线光电子能谱(XPS)、X射线衍射(XRD)、示差扫描量热(DSC)、热重分析(TGA)和静态接触角测试等手段对其结构和性能进行了表征,并通过单丝拔出实验研究改性前后纤维与环氧树脂之间的界面剪切强度(IFSS),探索了反应物配比、反应时间对表面性能的影响,并确定最佳改性条件.结果表明Cat-TEPA共沉积改性未影响纤维的结晶和热稳定性,改性后纤维表面浸润性得到改善,且适当增加反应时间和TEPA含量能够提高纤维和树脂之间的IFSS,当Cat-TEPA摩尔比为1:4,反应时间为24 h时效果最佳,与未改性纤维相比,界面剪切强度提升约44%.

Surface Modification of Ultra-high Molecular Weight Polyethylene Fiber by Catechol-tetraethylenepentamine

In recent years,research on interface modification based on dopamine has been greatly developed,but the high price of dopamine limits its practical application.Cheap catechol-tetraethylenepentamine(Cat-TEPA),similar to dopamine,can spontaneously polymerize and then deposit on the surface of various materials,exhibiting strong adhesion,reactivity,and no selectivity to the substrate.Surface modification based on Cat-TEPA has become a universal method suitable for practical applications.In this paper,ultra-high molecular weight polyethylene(UHMWPE)fiber was modified by Cat-TEPA.Transmission electron microscopy(TEM),infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),differential scanning calorimetry(DSC),thermogravimetric analysis(TGA),and the static contact angle investigations were used to characterize the structure and performance of the modified fibers.The interfacial shear strength(IFSS)between the fiber and the epoxy resin before and after modification was measured by monofilament extraction experiment.The effects of reactant ratio and reaction time on interface properties were explored and the optimal modification conditions were determined.The results show that Cat-TEPA modification does not affect the crystallization and thermal stability of the fiber,and the surface wettability of the fiber is improved after modification.An optimal IFSS increase of about 44%has been obtained when the molar ratio of Cat-TEPA is 1:4 and reaction time is 24 h.