环氧氯丙烷橡胶的热可逆共价交联

THERMALLY REVERSIBLE COVALENT CROSSLINKING OF CHLOROPROPYLENE EPOXIDE RUBBER

以环戊二烯二羧酸钾 [DCPD(COOK) 2 ]为交联剂 ,采用溶液反应法使环氧氯丙烷橡胶 (环氧氯丙烷均聚物 ,CER)交联 ,制得了凝胶含量达 88 75 %的交联CER ,研究了溶剂种类、反应温度、催化剂及交联剂用量对凝胶形成量的影响 .IR谱证明 ,DCPD(COOK) 2 与CER发生双端酯化而交联 ;反应溶解性试验表明 ,该共价交联聚合物具有热可逆转化特性 ,热可逆转化百分率随反应温度的提高。

Chloropropylene epoxide homopolymer (CER) crosslinked by DCPD ( COOK)(2) as crosslinker with 88.75% gel content was obtained by solution reaction, the effect of the kinds of solvent, the dosage of crosslinker and calalyst (TBAB), reaction temperature and time on the amount of polymer gel formation were studied. The results indicated that the crosslinking reaction accelerates with the acsension of the reaction temperature and time, increase of dosage of crosslinker and catalyst. Solvent affected the crosslinking reaction and the result indicated that the reaction was most efficient in DMF. It was proved by IR that the gel was generated through esterification between the chlorine on carbon of CER and the carboxylic salt group of the crosslinker by eliminate KCl. The test of reaction solubility of crosslinked CER react with maleic anhydride ( MA) indicated that the crosslinked CER exhibits a thermally reversible behavior due to the dimmer (decyclopentadiene)/monomer (cyclopentadiene) conversion of -DCPD- moieties in the crosslinkage of the copolymer, the percentage of thermally reversible conversion were decrease with the ascension of the reaction temperature, the amount of crosslinker increasing. Based on the crosslinking reaction, a novel thermoplastic elastomer of CER with higher heat-resistance and oil-resistance was obtained.