Study On Preparation Of Multi-Functional Liquid Rubber By Olefin Metathesis Reaction

Liquid rubber is a kind of important rubber material.It can be used as a plasticizer of rubber,and liquid rubber containing functional groups can also be used as a reaction component in special occasions such as sealants and adhesives.In this paper,liquid rubbers(LBR,LNBR)were prepared by the olefin metathesis reaction of cis-1,4-polybutadiene rubber(BR)and nitrile rubber(NBR)with different small molecular alkenes.The "target" groups in the small molecules were introduced into the structure of the rubber to achieve functionalization while reducing the molecular weight of the rubber.First,1-hexene was selected to undergo metathesis reaction with BR and NBR respectively to prepare liquid rubber with plasticizing function.The effects of reaction time,reaction temperature,1-hexene dosage and catalyst dosage on the reaction were investigated.The molecular weight of the reaction product was characterized by GPC,and the effects of different molecular weights of liquid rubber LBR on the processability and usability of SSBR/BR blends and LNBR on NBR blends were investigated.The research shows that by controlling the reaction conditions,BR and NBR can successfully prepare LBR and LNBR by olefin metathesis reaction with 1-hexene.Compared with the traditional commercial plasticizer V500 and DOTP,the rubber processability is improved,and the volatile and extraction resistance are significantly improved.Among them,LBR1 with molecular weight of 20000 and LNBR2 with molecular weight of 8000 can reach the ideal balance between processing performance and usability within the research range.In order to realize the versatility of liquid rubber,VTMO with trimethoxysilane and NAPM with amine antioxidant group were selected to undergo metathesis reaction with BR and NBR respectively to prepare LBR-VTMO with plasticizing/dispersing dual function and LNBR-NAPM with plasticizing /anti-aging dual function.Taking the molecular weights of LBR1 and LNBR2 as the target,the conditions for preparing LBR-VTMO with molecular weights close to 20000 and LNBR-NAPM with molecular weights close to 8000 were obtained through orthogonal test;At the same time,LBR-VTMO and LNBR-NAPM were added to BR and NBR matrices respectively to explore the effect of the addition amount on rubber properties.The results showed that addition of LBR-VTMO could significantly improve the dispersion effect of silica in BR blends,even better than that of Si69,in addition to plasticizing effect;The NBR blends added with LNBR-NAPM can significantly improve the aging resistance of NBR.When the amount of LNBR-NAPM is 8-11 phr,the aging resistance of NBR is equivalent to4010 NA and has no negative impact on other properties.