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为了提高白炭黑与橡胶的相容性,同时防止防老剂的挥发,采用γ-缩水甘油醚氧丙基三甲氧基硅烷与对氨基二苯胺(PPDA)的反应物对白炭黑进行表面改性,得到表面接枝防老剂的白炭黑。将改性白炭黑应用于天然橡胶(NR)中考察其增强与防老性能,并与炭黑/NR、未改性白炭黑/NR和Si69改性白炭黑/NR复合材料相比较(均添加防老剂4020)。结果表明,改性白炭黑/NR复合材料的焦烧时间延长,硫化时间缩短,白炭黑在橡胶中的分散性提高,同时具备更出色的力学性能。随着表面接枝防老剂含量的增加,改性白炭黑/NR复合材料的拉伸强度和撕裂强度比未改性白炭黑和Si69改性白炭黑/NR均有大幅提高。当接枝的PPDA含量达到5.27%(与白炭黑的质量比)时,其拉伸强度比未改性白炭黑/NR提高了90%,比Si69改性白炭黑/NR提高了73%,并接近炭黑/NR;其撕裂强度是未改性白炭黑/NR的5倍,Si69改性白炭黑/NR的2.5倍,炭黑/NR的2倍。另外,表面接枝防老剂的白炭黑/NR复合材料具有优异的抗热氧、抗臭氧和湿热老化性能;其抗臭氧老化性能优于添加通用防老剂4020的对比复合材料。
In order to improve the compatibility of silica with rubber and prevent the volatilization of the antioxidant, the silica was surface-modified with a reactant of γ-glycidoxypropyltrimethoxysilane and p-aminodiphenylamine (PPDA) , To obtain surface grafting antioxidant white carbon black. The modified silica was applied to the natural rubber (NR) for its reinforcement and anti-aging performance. Compared with the modified carbon black / NR, unmodified silica / NR and Si69 modified silica / NR composites Antioxidant 4020 is added). The results show that the scorch time of modified silica / NR composites is prolonged, the vulcanization time is shortened, the dispersibility of silica in rubber is improved, and the mechanical properties are better. With the increase of surface grafting antioxidant, the tensile strength and tear strength of the modified silica / NR composites increase significantly compared with unmodified silica and Si69 modified silica / NR. When the content of PPDA reached 5.27% (mass ratio to white carbon), the tensile strength increased 90% compared with that of unmodified silica / NR and 73% higher than that of Si69 modified silica / NR % And close to the carbon black / NR; its tear strength is 5 times that of unmodified silica / NR, 2.5 times that of Si69 modified silica / NR, and twice that of carbon black / NR. In addition, the surface grafted antioxidant white carbon black / NR composite has excellent resistance to hot oxygen, anti-ozone and heat aging properties; its anti-ozone aging performance is better than adding the universal antioxidant 4020 comparative composite.