Abstract:
Flexible electronic devices have developed rapidly in recent years, but there are also some drawbacks such as weak interface adhesion and poor energy absorption and buffer ability. Aiming at the above defects, a series of impact hardening polymer elastomer with adhesion (IHP-EA) is designed by
in situ crosslinking strategy using the combination of stable and dynamic crosslinking. Herein, the impact harden polymer (IHP) synthesized by silanol-terminated polydimethysiloxane (PDMS-OH) and trimethoxyboroxine (TMOB) constructed a dynamic crosslinking network to provide self-healing and energy absorption characteristics. The chemical crosslinked polydimethysiloxane (PDMS) network increased mechanical strength. Poly2-((((butylamino)carbonyl)oxo) methacrylate) (PBM) was prepared by free radical polymerization as an adhesion functional component to form high density hydrogen bonds with the substrate. The tensile strength and elongation at break of IHP-EA are 0.26 MPa and 177%, respectively, at strain rates of 50 mm/min. Normally, the toughness of PDMS materials rapidly decreased with the increasing of strain rate, while on the contrast, IHP-EA showed an obviously increasing toughness together with the increasing tensile rate, which indicated the significant strain rate responsiveness of IHP-EA. Therefore, IHP-EA has outstanding energy absorption and buffer effect, and the impact energy absorption efficiency could reach higher than 78% under an impact velocity of 4.43 m/s , much higher than that of conventional PDMS elastomer. In addition, IHP-EA has excellent interfacial adhesion performance, with the adhesion strength on glass substrate up to 198 kPa, almost 100 times higher than ordinary PDMS materials. In addition, IHP-EA also performed self-healing characteristic (healing efficiency exceeds 88%) and transparent performance (greater than 90%). These outstanding properties make the IHP-EA a potential candidate for application in flexible electronics and wearable protective materials.