A Study Of Microstructure Characteristics And Dynamic Mechanical Analysis Of SSBR

Solution-polymerized styrene-butadiene rubber (SSBR) samples with Differentmicrostructures were prepared in this experiment. The microstructure content,relative molecular mass and its distribution, and thermal characters of pure rubberswere studied.On the base, the influences of St and vinyl microstructures on dynamicmechanical characters of SSBR vulcanizates were discussed separately, and thephysical and mechanical properties of SSBR samples were also studied. Moreover, thedynamic mechanical characters and physical and mechanical properties of commercialSSBR and SSBR/ESBR1502 were further researched.The contents of SSBR microstructures were measured quantificationally by IR;The Segments of SSBR were random structures tested by ~1H-NMR; The results ofGPC showed that small molecules of SBR would increase and molecule massdistributions would become wide with increasing of St and vinyl; The results of DSCshowed that, with increasing of St and vinyl, the Tg of SSBR would be improved,the ranges of Tg would become wide, and specific heat transformation would decreaseon the whole; The curves of differential coefficient of SSBR would become wide withincreasing of St and vinyl. The effects of St on the curves of differential coefficient ismore than vinyl.The results tested by DMA showed that, with increasing of vinyl, the E′of SSBRwould gradually rise and the E″changes were not clear; The tanδof SSBR would goup at 0℃and hardly change at 50℃～60℃; The peak value of Tanδwould graduallycut down. And the integral area of tanδ～T curves would increase firstly, then decrease gradually. However, the area would always decrease if structures of St were manymore. With increasing of St, the E′of SSBR would also gradually rise and the E″changes were not clear; The tanδof SSBR would gradually go down at lowtemperature and go up at high temperature; The peak value of Tanδwould graduallycut down, And the integral area of tanδ～T curves would decrease; The curves ofE′～T,E″～T and tanδ～T all moved to high temperature, that meaned that the Tg wasimproved; The effects of St on DMA characters of SSBR were more than vinyl.The curves of E′～T,E″～T and tanδ～T of commercial SSBR had the sametrends with SSBR synthesized by ourselves; The system of SSBR/ESBR1502 canreach micro-blend-structures. So the characters of DMA were familiar with SSBRsynthesized by ourselves.Physical and mechanical properties showed that both tensile strength andhardness would increase with increasing of St and vinyl in the system of SSBR,commercial SSBR and SSBR/ESBR1502; Elongation at break and strength at 100％would be varied with increasing of St and vinyl.