Dynamic PEG–PLA/Hydroxyurethane Networks Based on Imine Bonds as Reprocessable Elastomeric Biomaterials

Abstract

The development of dynamic covalent chemistry opens the way to the design of materials able to be reprocessed by an internal exchange reaction under thermal stimulus. Imine exchange differs from other exchange reactions by its relatively low temperature of activation. In this study, amine-functionalized star-shaped PEG–PLA and an aldehyde-functionalized hydroxyurethane modifier were combined to produce PEG–PLA/hydroxyurethane networks incorporating imine bonds. The thermal and mechanical properties of these new materials were evaluated as a function of the initial ratio of amine/aldehyde used during synthesis. Rheological analyses highlighted the dynamic behavior of these vitrimers at moderate temperature (60–85 °C) and provided the flow activation energies. Additionally, the reprocessability of these PEG–PLA/hydroxyurethane vitrimers was assessed by comparing the material properties before reshaping and after three reprocessing cycles (1 ton, 1 h, 70 °C). Hence, these materials can easily be designed to satisfy a specific medical application without properties loss. This work opens the way to the development of a new generation of dynamic materials combining degradable PEG–PLA copolymers and hydroxyurethane modifiers, which could find applications in the shape of medical devices on-demand under mild conditions.

Orthogonal polymerization of aziridine with cyclic carbonates for constructing amphiphilic block copolymers

“…Block copolymers (BCPs) are produced via the chemical combination of two or more polymer segments with different structures. 1 Owing to the different performances of each polymer segment, diverse integrated functions are realizable by customizing BCPs with specific structures, thus enabling their application in the fields of thermoplastic elastomers, 2 nanolithography, 3 compatibilizers, 4 membranes, 5 solar cells, 6 batteries, 7 etc . 8–12 As critical functional BCPs, amphiphilic polymers comprising hydrophilic and hydrophobic segments exhibit unique responsive behaviors to different media, resulting in different polymer morphologies, thus facilitating their diverse applications, 13,14 e.g.…”