基于Diels-Alder反应的聚丙烯回收强化  

Enhancement of Polypropylene Recycling Based on Diels-Alder Reaction

作　　者：刘文东 牛慧 Wendong Liu;Hui Niu(Department of Polymer Science and Engineering,School of Chemical Engineering Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学化工学院高分子材料系,辽宁大连116024

出　　处：《高分子材料科学与工程》2023年第12期8-15,共8页Polymer Materials Science & Engineering

基　　金：国家自然科学基金面上项目(22278065)。

摘　　要：文中采用反应性加工方法将Diels-Alder(D-A)动态共价键接枝到商品化的等规聚丙烯中,在螺杆挤出机中一步法制备出具有热可逆交联结构的聚丙烯,并详细研究了接枝单体浓度、马来酰亚胺与呋喃基团比例等关键参数对交联聚丙烯力学性能的影响,特别是材料循环再利用时的性能变化规律。结果表明,可逆交联能够显著提高聚丙烯的弯曲模量和弯曲强度,材料的冲击强度也有一定改善;当接枝于聚丙烯侧基的呋喃适当过量于小分子交联剂双马来酰亚胺(即马来酰亚胺与呋喃官能团摩尔比为0.50)时,材料的增强效果最优。可逆交联聚丙烯经循环加工2次后,其力学强度仍优于未交联的商品化聚丙烯。此外,得益于D-A反应的热可逆性,交联聚丙烯具有与商品化聚丙烯相近的熔融加工性能。动态共价键的引入为聚丙烯的回收强化提供了新思路。Diels-Alder(D-A)dynamic covalent bonds were grafted into commercial isotactic polypropylene by reactive processing method,and polypropylene with thermoreversible cross-linking structure was prepared by a one-step method in screw extruder.The effects of grafted monomer concentration and maleimide to furan group mole ratio on the mechanical properties of cross-linked polypropylene were studied in detail.In particular,the material properties during recycling were investigated.The results show that reversible cross-linking can significantly improve the flexural modulus and flexural strength of polypropylene,and the impact strength is also improved.When the furyl groups grafted on the side group of polypropylene is super-stoichiometric moderately to the cross-linking agent bismaleimide(i.e.,the mole ratio of maleimide to furan group is 0.50),the highest properties are achieved.The reversible cross-linked polypropylene after two cycles of processing exhibits better mechanical properties than these of uncross-linked polypropylene.In addition,due to the thermal reversibility of D-A reaction,the cross-linked polypropylene presents the similar processing capability as commercial polypropylene.The introduction of dynamic covalent bond provides a new strategy for the enhancement of polypropylene recycling.

关 键 词：聚丙烯 DIELS-ALDER反应 回收 反应性加工 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]