改性硫黄对无钴天然橡胶的性能及与镀钴钢丝帘线黏合的影响

Effects of modified sulfur on properties of cobalt-free natural rubber and its adhesion to cobalt-coated steel cords

考察了自制的改性硫黄对无钴天然橡胶(NR)的硫化特性、物理机械性能、动态力学性能及与镀钴钢丝帘线黏合性能的影响,并与含钴胶料/镀黄铜钢丝帘线进行了比较。结果表明,随着改性硫黄用量的增加,无钴NR的硫化速率和交联程度均呈增大趋势,邵尔A硬度和拉伸性能变化不大;当改性硫黄用量为4.0份时,撕裂强度最佳;当改性硫黄用量为5.0份时,具有优良的低滚动阻力和高抗湿性;随着改性硫黄用量的增加,无钴NR/镀钴钢丝帘线的抽出力和附胶率呈增大趋势;当改性硫黄为5.0份时,无钴NR/镀钴钢丝帘线分别在湿热老化、蒸汽老化、盐水老化后的抽出力和附胶率与含钴NR/镀黄铜钢丝帘线相当或更大。

The effects of homemade modified sulfur on the curing characteristics, mechanical properties, dynamic me- chanical properties of cobalt-free natural rubber （NR） and its adhesion to cobalt-coated steel cord were investigated. And the adhesive properties of cobalt-free compounds with cobalt- coated steel cords were compared with those of cobalt-contai- ning NR compounds/brass-coated steel cords. The results showed that the vulcanization rate and crosslinking degree of the cobah-free NR compounds increased with the increase of amount of modified sulfur, and the Shore A hardness and ten- sile properties of NR vulcanizates changed little. When the modified sulfur was 4.0 phr, the tear strength was the best. When the modified sulfur was 5.0 phr, NR vulcanizates had excellent low rolling resistance and high wet resistance. The pull out force and rubber adhesion ratio of cobalt-free NR compounds/cobalt-coated steel cords increased with the in- crease of amount of modified sulfur, When the modified sulfur was 5.0 phr, the pull out force and rubber adhesion ratio of the cobalt-free compounds/cobalt-coated steel cords in the hot and humid aging, steam aging and salt water aging were equal to those of cobalt-containing compounds/brass-coated steel cords, even bigger.