摘要
以茂金属化合物亚乙基桥二茚基二氯化锆(rac-Et(Ind)2ZrCl2)为主催化剂、甲基铝氧烷(MAO)为助催化剂,实现乙烯/丙烯/8-呋喃-1-辛烯的三元共聚,制备了侧基含有呋喃基团的乙丙共聚物;再以不同结构的双马来酰亚胺为交联剂,通过Diels-Alder反应制备了具有热可逆交联结构的乙丙共聚物。利用核磁共振氢谱(1H-NMR)、差示扫描量热(DSC)、凝胶渗透色谱(GPC)等对共聚物结构进行了表征,利用溶胀实验、拉伸实验对交联聚合物性能进行测定。结果表明,通过改变交联剂结构和马来酰亚胺与呋喃的比例可以调节共聚物的交联程度,利用Diels-Alder反应的热可逆性实现了交联乙丙共聚物的重复加工。
The ternary copolymerization of ethylene/propene/8-furyl-1-octene was conducted with metallocene rac-Et(Ind)2ZrCl2 as the catalyst and methylaluminoxane(MAO)as the cocatalyst to synthesize the ethylene/propylene copolymer with furyl-side groups.The copolymerization was proved to be of high efficiency with controllable copolymer composition.The copolymer structures were characterized by 1H-NMR,DSC and GPC.Ethylene/propylene copolymers with thermoreversible cross-linking structure were prepared via Diels-Alder reaction using different bismaleimide molecules,that is,with–C6H4(CH2)C6H4―,―(CH2)6―,and―(CH2)12―as the middle segment of bismaleimide which were named as Ph2,C6,and C12,respectively,as the cross-linking agent.The cross-linking degree was determined quantitatively by equilibrium swelling measurements,and the properties of the cross-linked materials were determined by tensile test.Results showed that the cross-linking degree of copolymers could be controlled by changing the structure of cross-linking agent and adjusting the mole ratio of maleimide to furan.The cross-linking degree of the materials prepared by flexible bismaleimides C6 and C12 was more stable.Whereas for the cross-linked specimens obtained from rigid Ph2,the gel content and swelling ratio changed significantly after repeated processing.When bismaleimide was sub-stoichiometric,the cross-linking reaction could be fully implemented,so as to ensure the stability of cross-linking degree of the sample after repeated processing.The flexibility of thecross-linking agent could also promote the cross-linking reaction.In summary,the thermal reversibility of the Diels-Alder rings formed between the maleimide and furan groups rendered the cross-linked materials with repeatable processability.
作者
刘姝慧
牛慧
LIU Shuhui;NIU Hui(Department of Polymer Science and Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China)
出处
《功能高分子学报》
CAS
CSCD
北大核心
2020年第6期598-604,共7页
Journal of Functional Polymers
基金
中央高校基本科研业务费(DUT17LAB14)资助项目。
