拉伸过程中橡胶交联网络结构变化研究

摘要

研究拉伸过程中乳聚丁苯橡胶交联网络结构的变化情况.试验结果表明:硫黄用量对交联密度和交联键类型均有影响；微小变形下,利用交联密度通过统计力学理论计算得出的硫化胶模量理论值增量与实测值增量具有较好的一致性；在拉伸过程中,硫化胶总交联密度减小；与转变点(应力-应变曲线拐点)相比,断裂点硫化胶的总交联密度变化不大,但单双硫键交联密度增大,且增量与拉伸初期硫化胶多硫键含量线性相关,说明断裂的部分多硫键重组为单双硫键.%The change of cross-linking network structure of ESBR vulcanizate during tensile deformation was studied. The results showed that,the crosslink density and type of cross-linking bond were influenced by the addition level of sulfur. The measured incremental modulus of vulcanizate under small deformation was in agreement with the calculated value from crosslink density using statistical mechanics. The total crosslink density of vulcanizate decreased during tensile deformation. The total crosslink density at breaking point was similar with that near the transition point (inflexion point of stress-strain curve) ,but the number of single and double bonds increased, and the increase was linearly depended on the original amount of polysulfide bond, which indicated some broken polysulfide bond restructured to form single and double bond.