Effect On Abrasion Resistance Of Nitrile-butadiene Rubber Diaphragm With Additional Zinc Oxide

Rubber diaphragms are prone to abrasive wear,adhesive wear,fatigue wear and mechanical chemical degradation wear for long time working in serious environment,such as alternating loads,high temperature and corrosive media.Wear failure is a common failure form of rubber materials in large-scale mechanical equipments,the abrasion of rubber materials is restricted by many factors,including the material's characteristics such as ShoreA hardness,tensile strength and external factors such as load and environment temperature.The abrasion of rubber diaphragm is a complicated process,studying its frictional wear,failure form and failure mechanism has some guiding significance and economic benefits in improving the wear resistance of rubber products,and prolonging the service life of large-scale mechanical equipments.In this dissertation,the rubber diaphragm was taken as the experimental background,and the final goal was to improve the resistance of rubber diaphragm.The nitrile-butadiene rubber(NBR)was selected as the experimental materials.The dissertation was to study the effect of different ZnO(conventional ZnO,nano-ZnO,modified nano-ZnO)on the abrasion resistance of NBR.A variety of test methods were used to test the properties and study the abrasion resistance of NBR,including mechanical properties(tensile strength,tensile stress,elongation at break and ShoreA hardness),vulcanization characteristics,crosslink density,friction coefficient,wear loss of NBR.Besides,the microstructure,morphology and distribution of ZnO in NBR were analyzed by many characterization methods,such as X-rays diffraction(XRD),energy dispersion spectroscopy(EDS),fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM).Firstly,the wear behaviors of rubber diaphragm were analyzed,including the wear process,wear mechanism and molecular chain fracture process.The rubber diaphragm is prone to fatigue wear with continuous contraction and expansion.There are three stages and six morphologies in this process.The molecular chain fracture process of rubber diaphragm is divided into four stages.The most serious effect on the rubber diaphragmfailure is mechanical external force and hydrolysis reaction.Next,the primary properties of NBR filled with different ZnO were characterized.Finally,the properties of NBR containing modified/unmodified ZnO were compared,and the surface of NBR was characterized and analyzed.The key research focused on the tissue morphology of ZnO in NBR on its abrasion resistance.The relationship between ZnO and rubber abrasion resistance was summarized.In order to confirm the best amount of ZnO,the vulcanization characteristics of NBR with different amounts of ZnO were measured.The results indicates that the comprehensive performance of NBR is the best when add 5 parts of ZnO to 100 parts of the NBR.When EDS analyzed NBR with different ZnO,it was found that nano-ZnO has obvious accumulation tendency in NBR.Therefore,it was proposed to modify nano-ZnO and selected a reasonable surface modification method(surface coating),and a coating modification modifier(silane coupling agent KH550),also the modification mechanism of surface coating method was analyzed.The silane coupling agent does graft reaction with ZnO while hydrolyzing and condensing.The wear of NBR with three different ZnO was studied.The conventional ZnO rubber is the worst of all,there is severe abrasive wear and adhesive wear,the nano-ZnO rubber is the worse,and the modified nano-ZnO rubber is the best one for slight abrasive wear without adhesive wear.It shows that the modified nano-ZnO can improve the abrasion resistance of the NBR.