原位接枝改性白炭黑/炭黑对天然橡胶/反式聚异戊二烯并用胶性能的影响

摘要

考察了原位接枝改性白炭黑(SiO2)与炭黑(CB)并用对天然橡胶(NR)/反式聚异戊二烯(TPI)并用胶硫化特性、力学性能及动态力学性能的影响.结果表明,随着SiO2并用比的增加,NR/TPI混炼胶的焦烧时间和正硫化时间逐渐延长,门尼黏度逐渐增大,加工流动性降低,硫化胶的拉伸强度、300％定伸应力和回弹性逐渐下降,邵尔A硬度逐渐上升;当CB/SiO2(质量比)为40/10时,硫化胶的撕裂强度达到最大值(67.8 kN/m);当CB/SiO2为30/20时,耐磨性能达到最佳;当CB/SiO2为10/40时,硫化胶的2级和6级耐屈挠性能最好,分别达到5.4×105次与8.0×105次;SiO2的加入可同时改善NR/TPI硫化胶的抗湿滑性能、滚动阻力和动态生热,当SiO2用量为50份时,相比于CB用量为50份时,NR/TPI硫化胶的滚动阻力和动态生热分别降低23.8％和29.8％,抗湿滑性能提升8.86％.%The effects of in-situ grafting modified silica(SiO2)/carbon black(CB) on the curing characteristics,mechanical properties and dynamic mechanical properties of natural rubber (NR)/transpolyisoprene (TPI) blends were investigated.The results showed that with the increase of proportion of SiO2,the scorch time and curing time extended,Mooney viscosity increased and processing fluidity of NR/TPI compounds decreased,the tensile strength,modulus at 300％ and resilience of the vulcanizates decreased,meanwhile,Shore A hardness increased gradually.When CB/SiO2 (mass ratio) was 40/10,30/20,10/40 respectively,tear strength of the vulcanizates reached the maximum values of 67.8 kN/m,and wear resistance and flexing resistance (5.4 ×105 times for grade 2 and 8.0 × 105 times for grade 6) was the best.The wet resistance,rolling resistance and dynamic heat build-up of the vulcanizates were improved with the addition of SiO2,the rolling resistance and dynamic heat of the vulcanizates with 50 phr SiO2 decreased by 23.8％ and 29.8％ compared with those of the vulcanizate with the same amount of CB,meanwhile,the wet resistance increased by 8.86％.