Preparation And Application Of Epoxidized And Hydrogenated Nitrile Rubber

This article prepared successfully epoxidized and hydrogenated nitrile rubber(E-HNBR)by epoxidation and hydrogenation of NBR.On the one hand,we prepared a kind of special HNBR by E-HNBR reacted with anhydrides,whose chain backbone has epoxy group and its side group has ester group.This special HNBR possessed excellent low-temperature performance and oil resistance.On the other hand,we prepared epoxidized and hydrogenated hydroxyl-terminated lipuid nitrile rubber(E-HHTBN)by epoxidation and hydrogenation of hydroxyl-terminated lipuid nitrile rubber(HTBN),and it was applied to synthesis of polyurethane.The main research works are as follow:1.Epoxide nitrile butadiene rubber(ENBR)was prepared via in situ epoxidation from NBR reacted with acetic acid and hydrogen peroxide.ENBR was hydrogenated in the presence of a homogeneous catalyst.FTIR and 1HNMR proved the successful introduction of epoxy group and selective hydrogenation of carbon-carbon double bond.DSC analysis revealed that Tg of ENBR increased linearly with epoxy content,and that the existence of epoxy group could effectively weaken crystalline trend of E-HNBR.2.A part of epoxy group in E-HNBR reacted with anhydrides in order to introduce ester group into molecular chain of rubber.FTIR and 1HNMR proved that the successful synthesis of E-HNBR with ester group.DSC analysis revealed the existence of epoxy group and ester group could effectively eliminate the crystalline structure and improve flexibility of molecular chain.Tg of the E-HNBR with ester group declined as the carbon chain of ester group increased.The glass transition temperature of E-HNBR-g-heptyl group decreased by 9.1?C,coefficient of cold resistance under compression is up to 0.35.Furthermore,residual epoxy group and ester group extremely enhanced oil resistance of HNBR.3.We also took the methods of epoxidation and hydrogenation to synthesize E-HHTBN,and it was applied in the synthesis of polyurethane.The results of FTIR and 1HNMR proved that had successfully synthesized the epoxidized and hydrogenated hydroxy-terminated butadiene-acrylonitrile copolymer-based polyurethane elastomer(E-HHTBN-PU).FTIR and AFM revealled that introduction of epoxy group weakened the extent of microphase separation,which gives the reason that tensile strength increases and then decrease as the degree of epoxidation increases.Mechanical properties reach the maximum at 13%,tensile strength up to 35.4MPa and elongation at break being 448%.The E-HHTBN-PU exhibited excellent ozone aging resistance in the ozone aging test,because hydrogenation eliminated the unsaturated double bond.The oil resistance indicated that hydrogenated PUE was less oil resistance than unsaturated PUE,but fortunately,the existence of epoxy group enhanced oil resistance and even surpassed the unmodified HTBN-PU.