Synthesis And Application Of Functionalized Low Molecular Weight Polyisoprene

The two kinds of liquid polyisoprenes with different structures were prepared by means of anionic polymerization and mercapto-alkene click chemistry methods in this work.The structures of different liquid polyisoprenes were characterized with the help of FT-IR,~1H-NMR,GPC methods and so on,and they were incorporated into the SSBR filled with silica.The TEM,DMA,Tensile tester and other measurement methods were adopt to investigate the silica dispersion and static/dynamic properties for the filled composites.Comparing with several kinds of commercial plasticizer,the effect of F-LIR on above properties of the composites was studied.The optimal content of the F-LIR in the composites was determined based on the combination properties.At last,the effect of polymer microstructure produced by different modification methods and species of end-capping reagent on the silica dispersion in the SSBR system was discussed in details.The results showed that:1.Comparing with the traditional plasticizer,the LIR not only reduced the Mooney viscosity efficiently and improved the processability,but also joined in the curing process.It was easy to be extracted and compensated for the volatile defect of the traditional ones.Comparing with the LIR,the F-LIR improved the silica dispersion in rubber matrix,and kept the above advantages belonging to the LIR.It further enhanced the mechanical properties of the vulcanizates.In which,compared with the NPO filled sample and the sample without plasticizer,the tensile strength of F-LIR filled vulcanizates increased by 12.73%and 15.53%respectively.2.The siloxy group content increased with increase of F-LIR content.The silica dispersion was improved to large degree.It induced the enhancement of the mechanical properties.However,the rubber content increased with increase of F-LIR.It reduced the cross-linking density of the vulcanizates,because of the constant sulfur content.The mechanical properties were decreased to some degree.To sum up,the dynamical and mechanical properties of the composites were up to the maximum,when the F-LIR content is 4 phr.3.The results of different F-LIR filled SSBR composites showed that the higher3,4 structure content,the better slipping resistance.The blocking rate was the highest,because of the smallest volume of CMDS molecular.Meanwhile,the dimethoxy has the higher reactivity with silica,comparing with other groups in this work.Compared with other blocking modification LIR,the LIR-CMDS promoted the silica dispersion.In the case of grafting modification,the content of siloxy group was much more than that of blocking modification.Compared with the other F-LIR,the combination properties of the SSBR filled with 3,4-LIR-g-MTS was the best.