Aging Study And Life Prediction Of HNBR Vulcanizate Under High Temperature Oil And Water Environment

Rubber is an important sealing material in the petroleum industry.Due to the increasingly strict industrial development and high requirements for safety performance,the requirements for oil resistance of rubber are higher and higher.HNBR is the product of NBR through hydrogenation reaction,which greatly reduces the molecular unsaturation and makes it have better heat resistance than NBR;At the same time,it also has high tensile strength,tear strength and excellent wear resistance.However,in the actual service process,a certain degree of aging will also occur,which will affect the service life of rubber.Therefore,it is particularly important to study the aging phenomenon of HNBR vulcanizate and the factors affecting the service life of HNBR vulcanizate.This paper makes the following specific research around the aging and service life of HNBR vulcanizate.(1)In order to study the aging phenomenon of HNBR under actual working conditions,the effects of vulcanization system,raw rubber type and aging environment on the aging of HNBR vulcanizate were studied through accelerated aging test.The mechanical property loss of HNBR vulcanizate crosslinked by DCP vulcanization system is the lowest after aging.At the same time,with the increase of DCP content,the mechanical property loss of HNBR vulcanizate after aging is smaller,and the amount of auxiliary crosslinking agent TAIC will not have a great impact on the aging of HNBR vulcanizate.The higher the content of acrylonitrile in raw rubber,the better the aging resistance of its vulcanizate,and the smaller the loss of mechanical properties after aging.(2)In order to study the specific reasons for the aging of HNBR vulcanizate in oilwater environment at 150 ℃,through the aging of HNBR vulcanizate in independent environment,it was found that HNBR vulcanizate showed different aging behavior in different environments.The changes of HNBR vulcanizate before and after aging were characterized by FTIR,crosslinking density analysis,DMA and SEM.(3)In order to study the service life of HNBR vulcanizate,taking the internal compressive stress of HNBR vulcanizate as the standard,the service life of HNBR vulcanizate was evaluated by compressive stress relaxation test.The effects of curing system,raw rubber type,filler type,Si O2 particle size,Si O2 surface morphology,plasticizer and temperature on the stress relaxation of HNBR vulcanizate were studied,and then the service life of HNBR vulcanizate was affected.By studying the aging and compressive stress relaxation test of HNBR vulcanizate,the effects of different factors on the aging and stress relaxation of HNBR vulcanizate were obtained,which provided theoretical guidance for the service of HNBR vulcanizate under actual working conditions.