Abstract

Self-healable crosslinked thermosets can prevent catastrophic failure and extend their lifetime due to their ability to recover the material properties after physical damages. A promising method to develop effective self-healable networks in repeating events is intrinsic self-healing that involves the utilization of mainly dynamic covalent linkages. Most of intrinsic self-healable networks have been designed with soft polymers to achieve rapid void-filling ability at low temperatures; however, they exhibit weak mechanical properties. The current and advanced development of intrinsic self-healable networks requires the balance of toughness and flexibility.
My Masters’ thesis research has focused on the investigation of a new platform that allows for the development of heterogeneous thermoreversible networks. The platform centers on the exploration of reactive multidentate block copolymer (rMDBC) strategy to stabilize nanomaterials, particularly carbon nanotubes (CNTs). The rMDBC is designed with a pendant pyrene block that can bind to CNT surfaces through physical - interactions. A reactive furfuryl block can react with a polymaleimide to form thermally-reversible networks through dynamic Diels-Alder (DA)/retro-DA (rDA) chemistry. The formed rMDBC/CNT colloids are acted as multiple crosslinkers for macromolecular engineering approach to form a robust heterogeneous network in which CNTs are covalently integrated, thus leading to uniform distribution of CNTs in self-healable networks. Taking advantage of characteristics of polyurethane (PU) including shape memory and hydrogen bonding, the developed materials exhibit robust self-healability and potentially enhanced mechanical property and conductivity.