Reprocessable vinylogous urethane cross-linked polyethylene via reactive extrusion

Abstract

Reactive extrusion of a precursor polymer and a diamine cross-linker leads to reprocessable vinylogous urethane polyethylene vitrimers with desired rheological properties.

Scalable upcycling of thermoplastic polyolefins into vitrimers through transesterification

“…We obtain the activation energy for transesterification: E a ≈ 124 kJ/mol for PPvit. This is much higher than the quoted value for dioxaborolane metathesis, E a ≈ 16 kJ/mol, 19 and also higher than E a ≈ 108 kJ/mol for the exchange reaction of vinylogous urethanes, 21 suggesting our PPvit constitutes a more robust dynamic network.…”

“…After the conception of vitrimers 12 in 2011 in the seminal work of Leibler et al, dioxaborolane metathesis 19,20 and exchange of vinylogous urethanes 21 have been employed to introduce adaptable network in TPO. In one of the earlier works by Leibler et al it was demonstrated that the network dynamics is mediated by the exchange between B-O bonds and boronic ester groups.…”

Vitrimers: directing chemical reactivity to control material properties

“…Compared to real vitrimers, such weakly cross-linked thermoplasts show very limited resistance to dissolution by solvents. [66][67][68] In spite of such drawbacks, these 'vitrimerised thermoplasts' have attracted considerable attention, [66][67][68][69][70][71][72][73][74] considering the fact that they can be processed using usual thermoplastic processing techniques, while their properties can be improved in comparison to the bulk thermoplastic counterparts.…”

Linear Viscoelasticity and Flow of Self-Assembled Vitrimers: The Case of a Polyethylene/dioxaborolane System

“…1 Since then, the literature has focused on altering the exchange reaction (either catalytically controlled or catalyst-free) and adapting chemistries to different polymer backbones. 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27 Other studies explored the properties of vitrimer composites and the addition of nondynamic cross-links to the network. 14,28,29,30,31,32,33,34,35 These research efforts established that modifying vitrimer chemistry provides a pathway for tuning mechanical properties, 36,37,38 stress relaxation, 39,40,41,42 shape memory, 43,44,45 and the ability to self-heal and adhere to other materials.…”