A Transformable and Bulky Methacrylate Monomer That Enables the Synthesis of an MMA-nBA Alternating Copolymer: Sequence-Dependent Self-Healing Properties

In this study, we designed a methacrylate molecule with an alkyl-substituted trichloro salicylic acid pendant as a transformable bulky monomer to enable the synthesis of an alternating copolymer of methyl methacrylate (MMA) and n-butyl acrylate (nBA). The adamantyl-substituted methacrylate monomer (1-Ad) showed very low homopolymerization propensity in radical polymerizations, but afforded the alternating copolymer with nBA via copolymerization. The 1-Ad units in the resultant copolymer were quantitatively and selectively transformed into MMA via transesterification with methanol to yield the alternating copolymer of MMA and nBA. Its alternating sequence was clearly demonstrated by a structural analysis via C-13 NMR spectroscopy as well as the low reactivity ratios for the 1-Ad and nBA pair. Finally, we verified the superior self-healing ability of the alternating copolymer compared to that of the corresponding 1 : 1 statistical copolymer.

Automated summary

In this study, a bulky monomer with an alkyl-substituted trichloro salicylic acid pendant was designed to enable the synthesis of an alternating copolymer of MMA and nBA. The monomer showed low homopolymerization propensity but formed the alternating copolymer with nBA via copolymerization. The 1-Ad units in the copolymer were selectively transformed into MMA via transesterification, resulting in an alternating copolymer of MMA and nBA. Its alternating sequence was confirmed by structural analysis and the copolymer showed superior self-healing ability compared to the corresponding statistical copolymer.