针对氢化丁腈橡胶(HNBR)加工性能欠佳,柔韧性不足,成本较高等问题,创新性地采用并用胶技术,将加工性和耐热性能良好的金属氧化物硫化氯丁橡胶(CR)引入硫磺硫化HNBR过程进行混炼构筑具有“类互穿”(IPN)网络结构的混炼胶,然后引入改性芳纶纤维(AF)进一步提升IPN网络结构混炼胶的综合性能。以HNBR/CR混炼胶为基体,引入硅烷偶联剂(KH550)改性AF作为增强相,制备了高强度、高模量的AF/HNBR/CR复合材料。结果表明:随着CR用量的增加,并用胶硫化速率正硫化时间(t_c90)延长,共混胶的门尼黏度下降,有效提高加工性能,当CR用量为20份时门尼黏度达到最优为54.5;力学性能方面,硬度增加,强度与弹性呈下降趋势,且当CR用量20份时,硬度为61.34HA,拉伸强度为27.44MPa,达到最优。但是需要注意,当CR用量为20份时,并用胶的力学性能下降趋势明显;当CR用量≤20份时,并用胶仍保持优异的耐热油老化和耐热空气老化性能,但是耐油性随CR用量继续增加而开始降低。此外,热稳定性测试结果表明CR的加入提高了材料热分解温度。在最优的共混配比-HNBR/CR=(80/20)的情况下考察不同添加量改性AF对性能的影响。结果表明:随着KH550-AF含量增加,AF/HNBR/CR共混胶在加工性能、力学性能、耐老化性能和成本之间达到平衡。在HNBR/CR(80/20)体系中添加KH550-AF后在IPN结构中起到“铆钉”的角色,有效增加交联位点,弥补单一的IPN结构物理互锁不足的问题,其100%定伸应力显著提升至5.84MPa,300%定伸应力由7.25MPa提升至14.57MPa,撕裂强度由55.41N/mm提升至72.27N/mm。

In order to address the issues of poor processability,insufficient flexibility,and high cost of hydrogenated nitrile butadiene rubber (HNBR),this study innovatively adopted rubber blending technology.It introduced metal oxide-vulcanized chloroprene rubber (CR),known for excellent processability and heat resistance,into sulfur-vulcanized HNBR to construct a blended rubber with a “quasi-interpenetrating”(IPN) network structure through melt blending.Subsequently,modified aramid fibers (AF) were incorporated to further enhance the comprehensive performance of the IPN-structured blend.The research used HNBR/CR blended rubber as the matrix and introduced silane coupling agent (KH550)-modified aramid fibers (AF) as the reinforcing phase to prepare high-strength and high-modulus AF/HNBR/CR composites.The results showed that with the increase in CR content,the vulcanization rate (t_c90) of the blended rubber was prolonged,and the Mooney viscosity of the blend decreased,effectively improving processability.When the CR addition amount was 20 phr,the Mooney viscosity reached the optimal value of 54.5.In terms of mechanical properties,the hardness increased,while the strength and elasticity showed a downward trend.When the CR dosage was 20phr,the hardness was 61.34 and the tensile strength was 27.44MPa,both reaching the optimal levels.However,it should be noted that when CR content was 20 phr,the mechanical properties decline sharply.When the CR dosage was ≤20phr,the blended rubber still maintained excellent heat-resistant oil aging and heat-resistant air aging properties,but oil resistance decreased with the further increase in CR content.In addition,thermostability test results indicated that the addition of CR increased the thermal decomposition temperature of the material.Under the optimal blending ratio of HNBR/CR=(80/20),the effect of different addition amounts of modified aramid fibers (AF) on performance was investigated.The results showed that with the increase in KH550-AF content,the AF/HNBR/CR blended rubber achieved the best balance among processability,mechanical properties,aging resistance,and cost.After adding KH550-AF to the HNBR/CR (80/20) system,it acted as a ‘rivet’ in the IPN structure,effectively increasing cross-linking sites and making up for the insufficient physical interlocking of the single IPN structure.As a result,the 100% modulus was significantly increased to 5.84MPa,the 300% modulus was increased from 7.25MPa to 14.57MPa,and the tear strength was increased from 55.41kN/m to 72.27kN/m.