Vapor-phase synthesis of a reagent-free self-healing polymer film with rapid recovery of toughness at room temperature and under ambient conditions

Abstract

Rapidly self-healable polymer is highly desirable but challenging to achieve. Herein, we developed an elastomeric film with instant self-healing ability within 10 s at room temperature. For this purpose, a series of copolymers of poly(glycidyl methacrylate-co-2-hydroxyethyl acrylate) (poly(GMA-co-HEA), or pGH) were synthesized in vapor phase via initiated chemical vapor deposition (iCVD) process. The elastomer includes a large amount of hydroxyl group in 2-hydroxyethyl acrylate (HEA) moiety capable of forming rapid, reversible hydrogen bonding in room temperature, while glycidyl methacrylate (GMA) with rigid methacrylic backbone chain in the copolymer provides the mechanical robustness to the elastic copolymer. With the optimized copolymer composition, the pGH indeed showed instant recovery of the toughness within a minute; a completely divided specimen could be welded within a minute at room temperature under ambient conditions simply by placing the pieces in close contact, which showed the outstanding recovery performance of elastic modulus (93.2 %) and toughness (15.6 MJ·m-3). The rapid toughness recovery without supplementing any external energy or reagents (e.g. light, temperature, or catalyst) at ambient in room temperature will be useful in future wearable electronics and soft robotics applications.