丙烯腈含量对NBR混炼胶硫化反应的影响

采用差示扫描量热法(DSC)研究了丙烯腈(AN)含量和炭黑对丁腈橡胶(NBR)硫化反应的影响。研究表明,AN含量由18.8%(质量分数,下同)增加至43.3%,硫化胶的物理交联密度增加约20%,化学交联密度大大增加,增加约73%。NBR复合材料的硫化反应分两个阶段:第一阶段硫磺硫化反应,第二阶段硫键短化和双键交联反应。AN含量增加,两阶段分离明显,硫化温度降低,第一阶段放热量减小,第二阶段放热量增加。炭黑加入后,催化了硫化反应,提高了化学交联密度,降低了反应热,且起始硫化温度受丙烯腈含量的影响变小,由未加炭黑的34℃降低到12℃。此外,丙烯腈含量越低,硫化反应受炭黑的影响越大。

Effect of AN Content on Vulcanization Reaction of NBR Compounds

Effect of acrylonitrile(AN) content and carbon black on nitrile butadiene rubber(NBR)vulcanization reaction was studied by DSC in this paper.The results show that as AN content increases from 18.8% to 43.3%,the physical cross-linking increases by 20% and the chemical cross-linking is increased by 73%.The vulcanization of NBR compounds contains two stages: sulfur vulcanization and double bond crosslinking.When AN content increases,curing reaction temperature compound reduces,and heat release rate reduces at the first stage,while it increases at the second stage.After the addition of carbon black,the curing reaction is improved,chemical cross-linking density is increased and heat release of vulcanization reduces.With acrylonitrile content increasing,the initial curing temperature increases by 34 ℃ without carbon black,but only by 12 ℃ with carbon black.In addition,the content of acrylonitrile is lower,the influence of carbon black on curing reaction is larger.