Self-healing amino acid-bearing acrylamides/ n-butyl acrylate copolymers via multiple noncovalent bonds

Ryo Kudo; Sadaki Samitsu; Hideharu Mori

doi:10.1039/d4ra00800f

Self-healing amino acid-bearing acrylamides/ n-butyl acrylate copolymers via multiple noncovalent bonds

RSC Adv. 2024 Mar 6;14(11):7850-7857. doi: 10.1039/d4ra00800f. eCollection 2024 Feb 29.

Authors

Ryo Kudo¹, Sadaki Samitsu², Hideharu Mori¹

Affiliations

¹ Department of Organic Material Science, Graduate School of Organic Materials Science, Yamagata University 4-3-16, Jonan Yonezawa City Yamagata Prefecture 992-8510 Japan h.mori@yz.yamagata-u.ac.jp.
² National Institute for Materials Science 1-2-1, Sengen Tsukuba 305-0047 Japan.

Abstract

Four amino acid-bearing acrylamides, N-acryloyl-l-threonine (AThrOH), N-acryloyl-l-glutamic acid (AGluOH), N-acryloyl-l-phenylalanine (APheOH), and N-acryloyl-l, l-diphenylalanine (APhePheOH), were selected for copolymerization with n-butyl acrylate (nBA) to develop amino acid-based self-healable copolymers. A series of copolymers comprising amino acid-bearing acrylamides and nBA with tunable comonomer compositions and molecular weights were synthesized by free radical and reversible addition-fragmentation chain-transfer copolymerization. Self-healing and mechanical properties originated from the noncovalent bonds between the carboxyl, hydroxyl, and amide groups, and π-π stacking interactions among the amino acid residues in the side chains were evaluated. Among these copolymers, P(nBA-co-AGluOH) with suitable comonomer compositions and molecular weights (nBA : AGluOH = 82 : 18, M_n = 18 300, M_w/M_n = 2.58) exhibited good mechanical properties (modulus of toughness = 17.3 MJ m^-3) and self-healing under ambient conditions. The multiple noncovalent bonds of P(nBA-co-AGluOH)s were also efficient in improving the optical properties with an enhanced refractive index and good transparency.