Hybrid Modification Of Lignin And Preparation And Propeties Of Rubber Composites

With the gradual depletion of fossil resources and human attention to environmental protection issues,especially in the recent"two-carbon economy"background,natural polymer with the characteristics of recycling increasingly attracted people’s attention,how to realize the efficient use of waste has become a hot issue in current scientific research.Lignin,as a kind of biomass filler,exists in plant tissues in large quantities and has very rich reserves.When it is filled into rubber,it can often play the role of reinforcing and anti-aging.However,there are a large number of hydroxyl groups on the surface of lignin,which is easy to agglomerate,so the utilization rate is very low and it is often discarded or incinerated as papermaking waste liquid.If it is modified and used in rubber,it can not only transform waste into treasure to achieve high value-added application,but also conform to the national strategic policy of"reducing carbon emission",which has great strategic significance.In this paper,silica,graphene oxide and accelerant CZ materials were used to modify lignin in order to reduce the interaction between lignin molecules,improve its easy agglomeration and improve the interface compatibility with rubber matrix.Some of the main work completed is as follows:（1）LS hybrid materials with different lignin ratios were prepared by in-situ generation method and applied to NR composites to prepare LS/NR composites.The effects of different lignin and silica ratios in LS materials on the performance of LS/NR composites were explored.The results show that the tensile strength of LS/NR composites can be improved by 20.5%and 5.7%compared with AL/NR composites and Si O₂/NR composites,respectively,when the lignin proportion of LS materials is40%.（2）The silane coupling agents KH560 and KH570 were used to conjugate lignin and white carbon black,respectively,to prepare AL@KH560 and Si O₂@KH570.The effects of AL@KH560 and Si O₂@KH570 with different filling quantities on the properties of NR/ESBR composites were investigated.The results show that NR/ESBR composites have the highest crosslinking density when the filling amount of AL@KH560 and Si O₂@KH570 is both 20phr,and the comprehensive mechanical properties of rubber composites are the best,the wear resistance of vulcanized rubber is the best,and the anti-aging property is the best.（3）GKL hybrid materials with different GO ratios were prepared,and the effects of different GO ratios in GKL materials on the properties of GKL/NR/ESBR composites were explored.The results show that when the GO content of GKL hybrid material is 4%,the rubber composite filled with it has the best skid resistance.When the GO content of GKL hybrid material is 8%,NR/ESBR composites have the smallest rolling resistance.（4）The silane coupling agent KH560 was used to modify lignin,and AL@KH560and promoter LC were grafted and polymerized by the reaction of secondary amine and epoxy group to prepare a new rubber additive LC.The influence of different filling amounts of LC on the properties of NR/ESBR composites was explored.The results showed that filling 40phr with LC could shorten the positive vulcanization time of NR/ESBR composites by 33.2%,and filling 10phr with LC could increase the vulcanization rate of NR/ESBR composites by 27.1%.