丙烯酸乙酯/烯丙基缩水甘油醚共聚物的热可逆共价交联

研究了双环戊二烯基二羧酸及其铵盐对丙烯酸乙酯 /烯丙基缩水甘油醚共聚物的交联反应 ,对比了二者的交联速度 .用DSC评价了它们的热可逆转化行为 .制得了热可逆部分达 79 7%的共价交联环氧型丙烯酸酯橡胶

STUDY ON THE THERMALLY REVERSIBLE COVALENT CROSSLINKING OF ETHYL ACRYLATE/ALLYL GLYCIDYL ETHER COPOLYMER

The thermally reversible covalent crosslinking of epoxy acrylate rubber(%E%-p|ACM) which is a copolymer of ethyl acrylate/allyl glycidyl ether was studied by using two thermally reversible covalent crosslinking agents, i.e dicyclopentadienyl dicarboxylic acid and diammonium dicyclopentadienyl carboxylate.The effects of the crosslinker amount,crosslinking and retro|crosslinking temperatures on the crosslinking rate,yield of crosslinking and retro|crosslinking were investigated in detail.It has been found that both the crosslinking and the retro|crosslinking rates increase with the increasing of crosslinker amount.The highest yield of crosslinked polymer was beyond 60% and the efficiency of retro|crosslinking was as high as 79 7% when DCPD(COONH-4)-2 was used as crosslinker.It could be concluded that diammonium dicyclopentadienyl carboxylate was a more efficient crosslinking agent than its carboxylic acid.But for the effect of temperature on the yield of crosslinked polymers the best optium temperature was only around 70℃.In spite of what kind of crosslinking agent was used,the thermal irreversible covalent crosslinkage was present (20%～25%) in the crosslinked copolymer.The possible reasons for this were:(1) the retro|crosslinking was not high enough because the reaction temperature was lower than 160～220℃ (detn.by DSC);(2)there was thermal irreversible covalent ether bond formed in the course of the %E%-p|ACM crosslinking with the crosslinker; (3) free radical polymerization of CPD which formed under the retro|crosslinking conditions could happen.The analysis data by FTIR and DSC confirmed that the crosslinkage provided by crosslinking agent and the gained covalent crosslinked copolymer exhibits thermally reversible conversion behavior.