Research UHMWPE Fiber Surface Modification And Composite Material Properties

This dissertation firstly gives a rough description of UHMWPE’s development, superficial modification and composite materia etc. Based on this fact, a systematic research is made from the aspect of its modified and optimized technology.Then we study chromic acid treatment of UHMWPE fibers’ modified characteristics and make a further analysis of chromic acid solution ratio, treatment temperature and time’s influences on its properties. By way of scanning electron microscope, infra-red spectra, analysis of thermal and contact-angle performance, a conclusion can be drawn that there will be changes of UHMWPE fiber’s surface morphology and functional groups, crystallization, infiltration performance, when treating by chromic acid. The monofilament pulling out experiment also be done, aiming at transformation of UHMWPE fiber and epoxy bond strength before and after the chromic acid experiment. The optimal parameters of chromic acid:potassium chromate:water:concentrated sulfuric acid=7:12:150, treatment temperature80℃and processing time3minLLDPE is selected as the base composite of UHMWPE/LLDPE and a research is made on its processing procedure. First, we study mixed mode of UHMWPE fiber and choose banbury mixer, after comparing mixing features of open mill and banbury mixer and the kneaded composite materials’mechanical properties. Mixing process parameters conducted from the experiment are:RM-200A torque rheometer; mixing time10mins; setting temperature125℃, speed45rpm, ventilation and temperature in the mixing room. Molding temperature and time, fiber length and level, all these parameters will have an effect on stretch and flexibility of composite materials, and the optimal molding conditions are also confirmed by orthogonal experiment, which are:mold temperature130℃;molding time15mins, UHMWPE fiber level15%and fiber length of20mm.