Study Of Structure And Properties In Silica Filled Solution Styrene Butadiene Rubber Composite

The Green Tire conception is initiated since ninetieth decades of last century, these days, this kind of green tread with low pollution emission and energy consumption is mainly composed of solution styrene butadiene rubber (SSBR) filled with silica around the world. Depending on this, the influence of molecule mass (Mn) and distribution, coupling degree and other molecular structure parameters on processing properties, static and dynamic mechanical properties, and abrasion resistance of silica filled solution styrene butadiene rubber are studied in this thesis, guidelines to industrially producing and use of SSBR composites are expected. Detailed researches are as following:1 Rubber Process Analyzer (RPA) and Transmission Electron Microscopy (TEM) are used to analyze filler net-work structure and distribution, the result showed that, molecule mass of matrix has less influence on filler distribution; bound-rubber content is analyzed, Gel Permeation Chromatography (GPC) is used to analyze molecule mass of un-bounded rubber, which in case to get molecule information of bounded rubber, results showed that bound-rubber content is improved with higher molecule mass and coupling degree, bound rubber layer is mainly composed of longer polymer chains. 2. ¹H nuclear magnetic resonance (NMR) relaxation time analysis is used to get information of crosslink density, percent of free tangling chain ends in bounded rubber layer and matrix, the results showed that, percent of cross linked polymer chains and free tangling chain ends are influenced by molecular structure parameters; molecule mass between crosslink points are increased with increased molecule mass of matrix, but percent of cross linked part in bounded rubber layer is improved, percent of free tangling chain ends is reduced.3.Mooney viscosity analyzer and Rubber Processing Analyzer (RPA) are used comparing processing properties of 100% coupled SSBR (Star type), made by Beijing University of Chemical Technology, and commercial products of 2305 and SL552, the results showed that, since molecule mass is improved, while molecular dispersion is reduced in 100% coupled SSBR, the ML₁₊₄100℃value of Star type is increased in the gum, elastic modulus is also increased, and strain relaxation speed is reduced, polymer processing property is influenced to some extent.4. Mechanical and dynamic properties analysis results showed that, Star type shows higher ratio of modulus at 300% to 100%, lower elongation at break; rolling resistance of Star type is reduced by 13% compared with 2305, hysteresis parameter tan5 is increased at 0℃, so wet traction is improved; abrasion resistance is increased by 28% compared with 2305. The reason of all these improvements should be that, in SSBR Str type, percent of free tangling chain ends is reduced; crosslinked degree and filler/rubber interaction are improved by coupling structure. Aging resistance of Star type is also the best of these three samples. So SSBR Star type is better for tread use, can be popularized industrially.5. Properties of three kinds of coupled rubber were studied; results showed that reinforced rubber composites' mechanical properties and dynamic hysteresis are influenced by monomer styrene content, polymer processing property are influenced by 1, 2- structure of butadiene affects.