Study On Phisical Properties Of Nitrile Rubbers Vulcanizated At High Temperature

The study of butadiene-acrylonitrile rubber (NBR) contain various performanceindicators，including vulcanization characteristics，physicalproperties，compressionpermanent deformation， heat-resistant oxygen aging performance and vulcanizatescrosslinking density and crosslinking bonds type. Because of NBR oil resistance excellent，it was used to produce various types of sealing material. So, in this paper, thecomprehensive research was launched as the center of the compression permanentdeformation of NBR.The research contents three parts. The first part of NBR raw rubber，mixed makingrubber，the dosage of fillings and vulcanizates physical properties of6systems. And itwere got that NBR formulation and the most suitable for sealing process conditions. Thenext of the research based on the basis of the first part. In the second part，the mainresearch was sulfide dicumyl peroxide (DCP) that is increasing used in NBR at present.The influences on vulcanizates performance of high temperature vulcanization and thedynamics of sulfide reaction process were studied. The results shows that the mechanicalproperties and the aging performance of NBR cured by DCP were excellent，whosesuitable for making the seal products. While the high temperature vulcanization should bebased on the half-life time of sulfide DCP, dynamic process and phisical performance. Itwas unfavorable that DCP vulcanizating with zinc oxide and stearic acid. The mostsuitable curing temperature is180℃. Under this curing temperature，compressionpermanent of NBR vulcanized rubber was11.9%，tensile strength was12.1MPa，andtensile elongation rate was368%.Another important object is sulfur/promote system vulcanization NBR performance.Therefore，in the third part of the article, promoting agents and vice promoting agents were determining by regression analysis，and made contour line of the performance. At last，thevulcanization system was determined as NOBS/TMTD/S=2/1.5/1.On this basis，the hightemperature vulcanization experiment were done.On the other side，this research also the use of the nanometer ZnO instead of ordinaryindustrial zinc oxide as activator in study of NBR sulfide. Research found that nanometerZnO promoted curing reaction with reducing the activation energy of reaction rate andcompression permanent deformation of vulcanized rubber. At last，vulcanizationcharacteristics，vulcanization dynamics，vulcanizates phisical properties，crosslinkingdensity，crosslinking bonds type and heat resistance analysis with different temperaturevulcanizated were analyzed. It found that there is a direct correlation between performanceand structure of rubber. High energy crosslinking plays a leading role in improvingvulcanizates heat resistance and compression permanent deformation. It found that insulfur vulcanization system of NBR curing temperature is unfavorable if it was higher than180℃. Vulcanization compression permanent was13.3%， tensile strength was8.5MPa，tensile elongation rate was333%at180℃.