Vanillin-Based Polyschiff Vitrimers: Reprocessability and Chemical Recyclability

Abstract

In this study, dynamic imine covalent bonds were introduced into vanillin-based vitrimers networks, endowing thermosets with hot-reprocessing ability and chemical recyclability under acid hydrolysis. First, dialdehyde monomer, which was synthesized from lignin-derived vanillin monomer, was reacted with conventional amine cross-linkers to form dynamic imine bond networks. Even after three hot-processing cycles, the tensile strength and elongation at break of polyschiff vitrimers could be recovered at least up to 71.2 and 72.8%, respectively, through the imine metathesis reaction. Importantly, the dialdehyde monomers showed enhanced recyclability under strong acid solution and could be reused to regenerate polyschiff vitrimers. These characteristics of reprocessablility, recyclablility, and biobased monomer present a feasible way to satisfy the demands of sustainability.

Cross-linker control of vitrimer flow

“…5 A wide array of associative dynamic covalent chemistries have been employed in vitrimers, including transesterification, [17][18][19] olefin metathesis, 20,21 dioxaborolane exchange, [22][23][24] silyl ether exchange, 25 and several others. [26][27][28][29][30][31][32][33][34][35] Surprisingly, despite the number of reactions studied, there are no systematic studies that examine the effect of the cross-linker structure on vitrimer properties. In this paper, we show that small structural modifications to cross-links in a vitrimer can offer control over stress relaxation over a wide range, without affecting the stiffness or flow activation energy of the materials.…”

The Impact of Vitrimers on the Industry of the Future: Chemistry, Properties and Sustainable Forward-Looking Applications

“…Therefore, the attention of industries is gradually shifting toward alternative epoxies for thermosets and composites. In the light of this, here we report studies on triglycidyl ether of phloroglucinol extracted from algae [92], polyimine networks from vanillin [93] or fructose [42] and derivatives of lignin [88]. In particular, diglycidyl ethers of vanillyl alcohol and bisguaiacol show great mobility, stiffness and thermal resistance (comparable to commercial BPA-based resins, such as EPON 828 and EPON 862) when cross-linked with a cycloaliphatic diamine [88].…”

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.…”