Room temperature self-healable ionic polymers by incorporating ammonium and carboxylate salt

Abstract

In this study, we report the fabrication and characteristics of a self-healing polymer forming an ionically bonded network based on carboxylic acids and alkyl amines. The self-healing polymer forming an ionically bonded network is prepared from acrylic acid-containing carboxylic groups in the main chain and ammonium carboxylate salts derived from alkyl amines of varying lengths. The nature of the ion bonding between alkyl amines and carboxylic acids within the polymer matrix was analyzed using Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FT-IR). The self-healing polymer, incorporating ionically bound entities like ammonium carboxylate salts, demonstrated 100% self-healing efficiency at room temperature overnight, in contrast to the reference polymer without ion bonding. Various lengths of alkyl amines used to form ammonium carboxylate salts exhibited remarkable properties such as over 500% elongation at break, adhesive strength exceeding 300 gf, and light transmittance of over 90%, all dependent on the length of the alkyl chain.