纳米碳酸钙/二氧化硅复合粒子对丁苯橡胶物理机械性能的影响

采用溶胶沉淀法制备了纳米CaCO3/SiO2复合粒子,并用不同改性剂对其进行表面改性,考察了改性复合粒子对丁苯橡胶(SBR)物理机械性能的影响,同时与硬脂酸钠改性纳米CaCO3填充的SBR硫化胶做了比较。结果表明,CaCO3/SiO2复合粒子粒径为40～50 nm,大小均匀,表面粗糙,SiO2包覆在纳米CaCO3表面,具有核壳结构;硬脂酸钠改性复合粒子填充SBR硫化胶的拉伸强度、撕裂强度、永久变形和邵尔A硬度均大于改性纳米CaCO3填充SBR硫化胶,最大拉伸强度可达到13.6 MPa,两者的300%定伸应力和扯断伸长率相当;用硬脂酸钠和Si 69协同改性的纳米CaCO3/SiO2填充SBR硫化胶的拉伸强度、300%定伸应力、撕裂强度和邵尔A硬度均明显优于硬脂酸钠改性复合粒子填充的SBR硫化胶,最大拉伸强度达到14.1 MPa,扯断伸长率减小,低填充量时两者的永久变形差别不大,高填充量时前者的永久变形低于后者。

Effect of nano-calcium carbonate/silica composite particles on mechanical properties of styrene-butadiene rubber

The nano-CaCO3/SiO2 composite particles were prepared by a sol-precipitation method,the mechanical properties of the styrene-butadiene rubber(SBR) vulcanizates filled with the nano-CaCO3/SiO2 composite particles treated using different organic modifiers were investigated and compared with those of SBR filled with nano-CaCO3 modified with sodium stearate.The results showed that the CaCO3/SiO2 composite particles were 40-50 nm and uniform in size,rough in surface.SiO2 was coated on the surface of nano-CaCO3,exhibiting a core-shell structure.As the CaCO3/SiO2 composite particles modified with sodium stearate(CaCO3/SiO2-1) were filled in SBR,the tensile strength,tear strength,permanent set and Shore A hardness of SBR vulcanizate were much better than those of sodium stearate modified CaCO3 filled SBR vulcanizate,and its maximum tensile strength reached 13.6 MPa.The two SBR vulcanizates were well matched in modulus at 300% and elongation at break.When the CaCO3/SiO2 composite particles synergistically treated with sodium stearate and Si 69 were filled in SBR,the tensile strength,modulus at 300%,tear strength and Shore A hardness of SBR vulcanizates were much better than those of SBR vulcanizates filled with CaCO3/SiO2-1,and its maximum tensile strength reached 14.1 MPa,but elongation at break decreased,the permanent set of the two SBR vulcanizates was almost the same at lower loading level,while the former was smaller than the latter in this property at higher loading level.