Abstract
Vitrimers have emerged as a prominent research area in the field of polymer materials.Most of the studies have focused on synthesiz-ing polymers with versatile dynamic crosslinking structures,while the impact of chemical structure on aggregate structure of vitrimers,particular-ly during polymer processing,remains insufficiently investigated.The present study employed commercial maleic anhydride-grafted-high densi-ty polyethylene(M-g-HDPE)as the matrix and hexanediol as the crosslinker to facilely obtain fiber-shaped HDPE vitrimers through a reaction ex-trusion and post-drawing process.Through chemical structure characterization,morphology observation,thermal and mechanical properties in-vestigation,as well as aggregate structure analysis,this work revealed the influence of dynamic bonds on the formation of aggregate structures during fiber-shaped vitrimers processing.A small amount of dynamic bonds in HDPE restricts the motion of PE chain during melt-extruding and post-drawing,resulting in a lower orientation of the PE chains.However,lamellar growth and fibril formation during post-drawing at high tem-perature are enhanced to some extent due to the competition between dynamic bond and chain relaxation.The uneven morphology of fiber-shaped HDPE vitrimers can be attributed to the stronger elastic effect brought by dynamic bonding,which plays a more dominant role in deter-mining the mechanical properties of fiber-shaped vitrimers compared to aggregate structure.
基金项目
National Natural Science Foundation of China(22278065)
National Natural Science Foundation of China(22073015)
维普
万方数据