Vitrimer Chemistry Assisted Fabrication of Aligned, Healable, and Recyclable Graphene/Epoxy Composites

Abstract

The alignment is a key factor to fully exploit the potential of graphene in reinforcement of polymer composites. However, it is still a challenge to orientate graphene in thermosets because of the insoluble and infusible features of the later. In this paper, we report a facile and scalable hot press method to fabricate aligned graphene nanoplate (GnP)/epoxy composites by utilizing the dynamic character of epoxy vitrimer. The bond exchange and topological rearrangement associated viscous flow of epoxy vitrimer during hot press allows the spontaneous orientation of GnP in matrix because the 2D structure and volume exclusion effect. SEM images demonstrate the orientation of GnP, while tensile test reveals the significantly increased reinforcement effect of GnP on matrix after hot press. Moreover, the dynamic reaction of epoxy vitrimer confers good healability and recyclability to the aligned composites as confirmed by the nearly fully recovered mechanical properties of the healed sample after cutting, and the recycled sample after grinding. This work is expected to provide new opportunity for fabrication of aligned thermosetting composites.

Vitrimers: directing chemical reactivity to control material properties

“…As materials, part of the excitement for the developments in the area of vitrimers is also driven by the fact that they also hold promise as thermoset substitutes for the development of weldable, recyclable and reshapable composites. 76 Therefore, the development of vitrimer (nano)composites have attracted considerable interest in the past few years, as demonstrated by the numerous varieties of already implemented reinforcing agents, such as glass and carbon bers, 77-81 silica and aluminabased llers, [82][83][84][85][86][87][88][89] carbon dots and nanotubes, [90][91][92][93][94][95] graphene, [96][97][98][99] cellulose, 100 nanocrystals, 101 etc. 102 The most frequently reported systems used in this context are based on the original trans-esterication vitrimer chemistry, because of the widespread commercially available hydroxy-functionalized llers.…”

Sustainable End-of-Life Management of Wind Turbine Blades: Overview of Current and Coming Solutions

“…The materials, potentially usable as self-repairing composites extending the service life, provide also the option of easier and more efficient recycling. There are several works where structural composites with vitrimer matrix were developed [ 138 , 139 ]. Schmidt and Reynaud and colleagues [ 140 , 141 , 142 ] achieved reworkability of their bio-based epoxy/glass fiber composites through the introduction of transesterification catalysts.…”

Enriching an Exchangeable Network with One of Its Components: The Key to High-Tg Epoxy Vitrimers with Accelerated Relaxation

“…In the first one, the reaction between epoxides and carboxylic acids was used to prepare networks containing an equimolar amount of ester and alcohol functionalities that were taking part in transesterification reactions. These easy-to-access model vitrimers have been extensively studied by several groups, − but actually, they are neither real elastomers nor real thermosets since their glass transition temperature, T g , is close to the ambient temperature. In order to obtain high- T g vitrimers, which are required in many structural applications, synthesis from anhydrides rather than acids has been proposed as a way of densifying the network.…”