Flexible segments regulating the gelation behaviours of aliphatic polycarbonate gels with excellent shape memory and self-healing properties

Abstract

Aliphatic polycarbonates gels have received unprecedented attention due to their environmentally friendly and sustainable properties. However, traditional aliphatic polycarbonates gels lacking functionalization properties are not able to meet the requirements of future innovations. Based on this situation, in this study, novel functionalized aliphatic polycarbonate gels PEG2000-b-P(TMC-co-MCC)n are developed. The formation of hydrogen bonds network endows the gel with good comprehensive performances. Accordingly, the gel possesses a tensile strength and stretchability up to 2.62 MPa and 397.7%, presents a shape recovery rate of 97.7% in 9 s at 30 °C and also can repair crack at room temperature for 4.5 h without any external stimulation. Furthermore, these performances can be regulated by the ratio of the flexible segment, and the specific relationships between them are also presented. Notably, the cross-linking mechanism of the gels PEG2000-b-P(TMC-co-MCC)n is also proposed. Significantly, the transition states, energy barriers and reaction enthalpies of each step in the formation of oligomers by ring-opening polymerization of small molecules are calculated by density functional theory to deepen the understanding of the reaction mechanism. This aliphatic polycarbonate gel with excellent shape memory and self-healing properties provides prospects for developing the biomaterials such as surgical sutures and stents, as well as flexible electronics.