Study On The Preparation And Properties Of Functionalized Hydrogenated Nitrile Rubber

Hydrogenated nitrile rubber is a special elastomer material with excellent comprehensive performance,which has the characteristics of high temperature resistance,oil resistance,and aging resistance.However,the contradiction between oil resistance and low temperature resistance has become one of the limitations restricting the expansion of the application of hydrogenated nitrile rubber.In this study,we prepared functionalized hydrogenated NBR graft copolymers by epoxy ring opening modification and graft modification.The aim was to reduce the conflict between oil resistance and low temperature resistance of hydrogenated NBR.The research of this thesis has the following main parts:1.The epoxidation of nitrile rubber was modified by acetic acid and hydrogen peroxide,and then the epoxidation and hydrogenation were modified by catalytic hydrogenation to prepare epoxy-hydrogenated nitrile rubber,and the effects of epoxidation and hydrogenation modification on the preparation and structure of epoxy-hydrogenated nitrile rubber were investigated;then the brominated carboxylic acid was used for ring-opening reaction with it to prepare brominated hydrogenated nitrile ester,and the effects of different chain lengths of brominated carboxylic acid on the ring-opening rate and structure were mainly studied.The products were characterized by 1H-NMR,FT-IR,DSC and TGA,and the glass transition temperature was obtained to decrease gradually with the increase of the ester group side chain length.The properties of brominated hydrogenated nitrile ester rubber vulcanizates were studied,and the results showed that the oil resistance of brominated hydrogenated nitrile ester rubber vulcanizates was greatly improved,and the vulcanization time of the vulcanizates was shortened by 1/2?3/4 compared with that of hydrogenated nitrile rubber vulcanizates.2.The hydrogenated NBR was modified by grafting with benzoyl peroxide as initiator and cashew phenol as grafting monomer using free radical emulsion polymerization method to prepare hydrogenated NBR/cashew phenol graft copolymer,and the effect of grafting reaction on the structure and properties of the graft copolymer was mainly studied.The products were also characterized by 1H-NMR,FT-IR and DSC tests.The results showed that the glass transition temperature of the hydrogenated nitrile/cashew phenol graft copolymer decreased gradually with the increase of the grafting rate,and the glass transition temperature decreased to-31? when the grafting rate was 18.9%.It was also found that the graft copolymers showed improved oil resistance,especially in 15#aviation hydraulic fluid,where the mass change rate was below 5%.