Natural glycyrrhizic acid: improving stress relaxation rate and glass transition temperature simultaneously in epoxy vitrimers

Abstract

Epoxy vitrimers based on transesterification reactions (TERs) is a kind of recyclable thermosets which have been developed prosperously in recent years. However, the good thermal performance and the quick network...

Facile in situ construction of a covalent adaptable network polyester vitrimer with advanced performance in repairability, foamability and recyclability

“…The preparation of vitrimers is complicated and consumes several hours or an even longer time due to the slow crosslinking reaction rate. 32 In this work, strategies of NGP and the tertiary amine structure (internal catalyst) were used to synergistically catalyze the reactions, preparing the vitrimer via a green and efficient one-pot process in less than 8 min. As shown in Scheme 1, samples were processed in an internal mixer at 270 °C for only 3.5 min, and they underwent transesterification and crosslinked reactions, as presented in Scheme 1(b).…”

“…The preparation of vitrimers is complicated and consumes several hours or an even longer time due to the slow crosslinking reaction rate. 32 In this work, strategies of NGP and the tertiary amine structure (internal catalyst) were used to synergistically catalyze the reactions, preparing the vitrimer via a green and efficient one-pot process in less than 8 min. As…”

Reprocessable, Self-Adhesive, and Recyclable Carbon Fiber-Reinforced Composites Using a Catalyst-Free Self-Healing Bio-Based Vitrimer Matrix

“…Generally, the gel content is proportional to the cross-link density of the network. , As the ratio increases from 0.6 to 1.0, the gel content increases from 94.1 ± 0.9 to 99.4 ± 0.2%, which also confirms an increase in the cross-link density. The T g of the TOTGE–MDA vitrimers can be obtained from the tan δ curves. − As can be seen in Figure b, the T g of the TOTGE–MDA vitrimers increases from 60.5 °C (TOTGE–MDA 0.6 ) to 82.6 °C (TOTGE–MDA 1.0 ) because the number of active amino hydrogen atoms increases rapidly as the stoichiometric ratio increases, and these hydrogen atoms form bonds with the epoxy groups, thereby forming a highly cross-linked structure. Meanwhile, the rigid MDA structure restricts the flow of molecular chain segments, thereby increasing the cross-link density and T g of the TOTGE–MDA vitrimers.…”

Synthesis and characterization of new bio-based poly(acylhydrazone) vanillin vitrimers

“…37,38 Nevertheless, the fact that T v s are lower than T g s does not affect the applicability as thermosets at room temperature due to the high values of the T g obtained for these materials, in contrast to what happens in other vitrimers where the creep resistance behavior could be compromised. [39][40][41]…”