沉淀法白炭黑对热塑性天然橡胶性能的影响

王文志　 吴国锋　 林硕　 章永化　

摘　要：以沉淀法白炭黑为填料、高密度聚乙烯(HDPE)和天然橡胶为原料,采用动态硫化技术制备了热塑性天然橡胶(TPNR),考察了沉淀法白炭黑用量对TPNR物理机械性能和耐磨性能的影响,研究了沉淀法白炭黑填充TPNR的热稳定性、结晶性和动态力学性能,并用扫描电子显微镜观察了TPNR的相态结构.结果表明,当沉淀法白炭黑用量为40份左右时,TPNR的拉伸强度、100%定伸应力和撕裂强度出现最大值,当沉淀法白发黑用量为10份时,TPNR的体积磨耗达到最小值,沉淀法白炭黑的适宜用量为20份;沉淀法白炭黑的加入改善了TPNR的热稳定性和动态力学性能,提高了TPNR的结晶温度、熔融温度和玻璃化转变温度;TPNR的拉伸断面出现了塑性形变的HDPE形成的条状物,说明沉淀法白炭黑具有良好的增强作用.
关键词：天然橡胶;高密度聚乙烯;沉淀法白炭黑;动态硫化热塑性弹性体;物理机械性能;结晶;热稳定性;动态力学性能
分类号：TQ332.5 　文献标识码：B
文章编号：1000-1255(2009)03-0241-04

Effect of precipitated silica on properties of thermoplastic natural rubber

Wang Wenzhi（Department of Polymer Science,South China University of Technology,Guangzhou 510640,China）　 Wu Guofeng（Department of Polymer Science,South China University of Technology,Guangzhou 510640,China）　 Lin Shuo（Department of Polymer Science,South China University of Tropical Agriculture,Danzhou 571731,China）　 Zhang Yonghua （Department of Polymer Science,South China University of Technology,Guangzhou 510640,China）　

Abstract：The thermoplastic natural rubber (TPNR) was prepared by dynamically vulcanizing with natural rubber,high density polyethylene (HDPE) and filler precipitated silica.Effects of different precipitated silica amount on the mechanical properties and wear resistance of TPNR were investigated,the thermal stability,crystallization and dynamic mechanical properties were also studied.The phase structure of TPNR was observed by scanning electron microscope.The results showed that the tensile strength,modulus at 100% and tear strength reached maximum when precipitated silica was 40 phr,the wear volume reached minimum when precipitated silica was 10 phr,and the optimum amount of precipitated silica was 20 phr.The thermal stability and dynamic mechanical property of TPNR were improved,and the crystallizing,melting and glass transition temperature of TPNR were enhanced by adding a little amount of precipitated silica.The bar formed by plastic deformation of HDPE confirmed the enhancement of precipitated silica.
Keywords：natural rubber;high density polyethylene;precipitated silica;dynamically vulcanizled thermoplastic elastomer;mechanical property;crystallization;thermal stability;dynamic mechanical property