Study On High Performance Oil-resistant Hydrogenated Natural Rubber

Natural rubber(NR)is a renewable hydrocarbon resource with low cost,high strength,high elasticity,high cold resistance,and is widely used.However,due to the existence of a large number of irregular reactive double bonds on the main chain of the NR,its thermal oxygen stability is seriously affected,and due to its non-polar structure,oil resistance has inherent defects,which limits the application of natural rubber.In this paper,starting from the molecular structure of natural rubber,a polar ester group was introduced into the double bond of the natural rubber by the method of thiol-ene click chemistry,which successfully improved the oil resistance of natural rubber.Further,the solution hydrogenation method was used to eliminate the remaining active double bonds of the main chain,and a new type of hydrogenated natural rubber with high comprehensive properties such as aging resistance and oil resistance was prepared.The main research contents are as follows:1.By thiol-ene click chemistry method,the mercaptan containing ester groups with different chain lengths were grafted onto the natural rubber molecular main chain to prepare two kinds of esterified natural rubber.Natural rubber grafted with methyl thioglycolate(NRL-MT)and natural rubber grafted with ethyl thioglycolate(NRL-ET).The effects of reaction time,latex concentration,amount of mercaptan,and amount of ammonia on the grafting rate of esterified natural rubber were studied.The change of glass transition temperature and thermal stability with the number of grafted ester groups were investigated.It was found that the oil resistance of NRL-MT and NRL-ET were significantly improved by the oil resistance test of the esterified natural rubber.2.Solution homogeneous catalytic hydrogenation of NRL,NRL-MT and NRL-ET were carried out respectively.Explored the effects of reaction time,reaction temperature,catalyst amount and other factors on the hydrogenation effect of different monomers,and it was found that the presence of ester group is beneficial to the hydrogenation of natural rubber.The vulcanized rubber of the hydrogenated sample was tested for aging resistance,mechanical properties,and oil resistance,and the change of comprehensive properties of the prepared new hydrogenated natural rubber were analyzed.