采用固相法制备了玉米淀粉接枝马来酸酐(MAH)和苯乙烯(St)的共聚物Starch-g-MAH-St(SMS)。采用机械共混法制备了接枝改性淀粉/丁苯橡胶(SMS/SBR)复合材料,研究了复合材料的力学性能、热空气老化性能、动态力学性能以及微观形态。结果表明,SMS/SBR复合材料的力学性能优于未改性淀粉/SBR复合材料和纯SBR。当苯乙烯和MAH单体用量都为原淀粉质量的10%且SMS的用量为20 g/100 g SBR时,SMS/SBR复合材料的力学性能最佳。经100℃热空气老化48 h后,复合材料的拉伸强度仍可达10 MPa。与纯SBR硫化胶相比,SMS/SBR复合材料的玻璃化转变温度(Tg)降低。微观形态分析显示,淀粉经改性后粒子尺寸减小,在SBR中的分散性得到了改善,与SBR基体的相容性得到了提高。
Starch-g-MAH-St(SMS),prepared by the solid state reaction method,is the graft copolymer of corn starch,maleic anhydride(MAH)and styrene(St).SMS/styrene-butadiene rubber(SBR) composite was prepared by mechanical blending.The mechanical properties,hot air aging properties,dynamic mechanical properties and micro morphology were investigated.The results show that the mechanical properties of SMS/SBR composite are superior to those of starch/SBR composite and vulcanized SBR.When the charging amounts of St and MAH are both 10% of the weight of starch and the content of SMS is 20 g per 100 g SBR,SMS/SBR composite has the best mechanical properties.The tensile strength of composite is 10 MPa after hot air aging at 100℃ for 48 h.The glass transition temperature(Tg) of SMS/SBR composite is lower than that of vulcanized SBR.The micro morphology analysis shows that the size of starch particle is decreased,the dispersibility of starch is increased and the compatibility between starch and SBR is improved after modification.