Preparation And Performances Of Sulfide/Siloxane-Containing Di-Functional SSBR

The preparation technology of green tire with difunctional SSBR has an important industrial application. In this thesis, difunctional SSBR were initiated by benzyl methyl sulfide lithium (BMSL) and 2-methyl-1,3 dithiane-2-lithium (MDTL) and end-capping with different structure of siloxane reagents through anionic polymerization. The thesis studied synthesis conditions and activity of the initiators, capping regular of the capping reagents. The thesis analyzed the micro structure of polymer with GPC, HNMR and characterized the performance of SSBR with universal tensile testing machine, torsion vulcanization tester, DMTA, RPA, Magnetic Resonance Crosslink Density Spectrometer.BPSL prepared at -78? THF as the solvent, the excess of n-butyllithium over 10% than Benzyl phenyl sulfide, at least 2 hours of reaction has a 30% initiation rate. The PDI of polymer is wide and it has bad storage stability under low temperature. The benzyl phenyl (methyl) sulfide has an activity of pyrogenic decomposition and it can accelerate sulfur vulcanization through bond broken.Studies about some siloxane capping reagents have shown that 3-chloropropyl trimethoxy silane and 3-Chloropropyl dimethoxy methyl silane have up to 90% of capping rate. Others capping rate is close to 70%. The smaller the number of R and the lower the capping rate. The couping ratio of the modified SSBR capped with 3-Chloropropyl dimethoxy methyl silane is lowest under the low molecular weight. The smaller the number of R, the lower the couping ratio.When the molecular weight is low; The couping ratio is about 40%. When the molecular weight adds up to more than a hundred thousand, the couping ratio can drop down to below 10% and the ratio does not change much under different post process.Studies about a dozen modified SSBR have shown that the difunctional SSBR initiated by BMSL have a higher crosslink density and the wet skid resistance, rolling resistance are improved obviously. The difunctional SSBR capped with 3-chloropropyl trimethoxy silane has the better performance tan ? at 60? is 0.101.The mechanical property is excellent, dispersion effect of the filler is better and the Payne effect is lower than the modified SSBR of other brands. The difunctional SSBR initiated by MDTL has an outstanding mechanical properties, a high bond rubber content and has formed a network structure of rubber-filler. The bound rubber content of difunctional SSBR capped with N-(3-triethoxysilylpropyl) 4,5-dihydroimidazole is high up to 20%.