Vitrimers: directing chemical reactivity to control material properties

Abstract

In this minireview, we survey recent advances in the development of vitrimer materials. Focus on how to chemically control their material properties is used to highlight challenges for boosting the potential of this emerging class of polymer materials.

The effect of polarity on the molecular exchange dynamics in imine-based covalent adaptable networks

“…22 For many polymeric materials, the effect of such network characteristics has been evaluated for their influence on the material properties at the macroscopic level. 21,24,38 However, as the dynamic-mechanical properties of these materials are directly influenced by the underlying molecular exchange reaction, 22,39,40 further understanding of the specific effects of polymer composition on the molecular bond exchange of dynamic covalent bonds in CANs is still essential. 36,41 Tailoring the flexibility of polymer chains is a classic example of a commonly applied parameter to tune material properties, and a conventional approach for enhancing this flexibility is by incorporating ethylene oxide (EO) moieties in the polymer, 42 as the energy barrier for rotation of the C-O bond in ethers is considerably lower than C-C bond rotation in alkanes.…”

Recyclable Organocatalyzed Poly(Thiourethane) Covalent Adaptable Networks

“…In view of the increasing amount of plastic generated, the recycling of this type of polymers is extremely important to prevent them from ending up in landfills and contaminating the environment. The development of covalent adaptable networks (CANs), covalently crosslinked polymers with the ability to be reshaped, to flow and to self-repair, represents a promising approach to improve the lifetime and recyclability of the thermosetting polymers [1][2][3][4].…”

Re-usable thermally reversible crosslinked adhesives from robust polyester and poly(ester urethane) Diels–Alder networks

“…These are exceptional results compared to the general drawback of CAN creep behaviour reported elsewhere. 26,27 The relative failure temperatures observed in the creep experiments ( performed on bonded samples under high load) correlate with the temperatures in DMTA where there is a substantial change in stiffness observed. These temperatures observed for DA-1 are remarkably close to the gel point temperature of 92°C reported by Bowman et al 20 for the Diels-Alder network formed from BMI monomer and a trifunctional furan monomer.…”

“…12 Despite the promise of CANs, they commonly exhibit creep deformation which is an important drawback. 26,27 There is a need to demonstrate creep resistance under load, especially for high performance applications requiring long term dimensional stability.…”