活性氯型丙烯酸酯橡胶的热可逆共价交联及力学性能

Thermally reversible covalent crosslinking and mechanical properties of acrylic rubber containing active chlorine

利用环戊二烯在常温下自动二聚成双环戊二烯(DCPD)和在高温下DCPD又可解聚成环戊二烯的热可逆Diels-Alder反应,将双环戊二烯二甲酸钾犤DCPD(COOK)2犦引入活性氯型丙烯酸酯橡胶(ACM)中,使其与活性氯原子反应形成热可逆共价交联结构,制备了可高温热塑加工而低温下又具有较好力学性能的新型热塑性弹性体,研究了交联剂种类及用量、交联温度、交联时间、相转移催化剂四丁基溴化铵、加工次数等对活性氯型ACM力学性能的影响。结果表明,DCPD(COOK)2对活性氯型ACM具有较强的反应活性;四丁基溴化铵的加入有利于DCPD(COOK)2在活性氯型ACM中的分散,并显著提高胶料的力学性能;活性氯型ACM热可逆共价交联胶料可重复加工,且经过三次加工后力学性能变化不大。

The cyclopentadiene could convert to dicycoperntadiene(DCPD) at room temperature and DCPD could convert to cyclopentadiene at high temperature.The former was a typical Diels-Alder reaction and the latter was its retro-reaction.The above reversible reactions were applied to acrylic rubber(ACM)containing active chlorine in order to form thermoplastic elastomer with good heat resistant.The potassium dicyclopentadiene formate[DCPD(COOK)2] was induced into ACM containing active chlorine by ester reaction and formed a crosslinking structure with reversibility at high temperature.The effects of type and content of DCPD(COOK)2,crosslinking temperature,crosslinking time,the phase transfer catalyst of tetrabutylammonium bromide(TBAB) and its dosage,process times on the mechanical properties of ACM containing active chlorine were investigated.The results showed that DCPD(COOK)2 had better reactive ability with ACM containing active chlorine;it could be lead to the better dispersion of DCPD(COOK)2 in ACM containing active chlorine when TBAB was added to the composition and the mechanical properties of ACM containing active chlorine increased distinctly;the thermally reversible covalent corosslinking compositions based on ACM containing active chlorine could be reprocessed and their mechanical properties had no obvious change after three times. $$$$