Study On The Performance Of Styrene-butadiene Rubber And Nitrile Rubber Modified By PTFE

Rubber is a highly elastic material with reversible deformation, widely used in various areasof industry, such as tires, rubber hose, sealing materials, etc. The application of both physical andchemical means to improve the performance of the rubber material in several fields with theunique features is considered as an attractive domain in polymer science. In this paper, PTFE wasselected as a modifier which is rarely reported to modify styrene-butadiene and nitrile rubber,expecting to improve the performance (weather, corrosion, stain, solvent and heat resistance,especially oil resistance) with element F introduced. The content of this thesis is divided into twoparts:The first part, SBR/PTFE was produced via the latex compounding method. The resultsindicate that PTFE could significantly enhance oil-resistance of SBR, which has a basicallyproportional relationship with the mass of PTFE dispersion. As the content of PTFE is40%-50%,SBR/PTFE has a large change for the rate in approximately28%, close to the nitrile rubber’s oilresistance standard of25%. In addition, there are also some improvements in physical andmechanical properties. For SBR/PTFE system, the largest increase in hardness exists in the blendratio of90/10; in the blend ratio of80/20, tensile strength reaches to maximum. Tensile elongationshowed a decreasing trend with the content of PTFE increases. Considering comprehensively,when the content of PTFE is10%to20%in the SBR/PTFE, the rubber has an optimalperformance in scorch resistance and processing safety.The second part, latex compounding and mechanical compounding method were used toprepare NBR/PTFE. For NBR/PTFE which blends by latex compounding method, there is noobvious increase of oil resistance with the adding of PTFE dispersion. The largest increase inhardness appears in the blend ratio of95/5. With the increase of PTFE content, tensile strengthand tensile elongation show a decreasing trend, the minimum loss exists at the blend ratio of95/5.Considering comprehensively, when the content of PTFE is5%to10%, the rubber has anoptimal performance in scorch resistance and processing safety. For NBR/PTFE which blends bymechanical mixing, there is same performance trends, but slightly smaller than the latexcompounding ones. However, there are a sharp difference in both tensile strength and300%elongation strength of the latex compounding one and the mechanical mixing one, probablybecause PTFE particles played a reinforcing role in the latter.