Smart "All Acrylate" ABA Triblock Copolymer Bearing Reactive Functionality via Atom Transfer Radical Polymerization (ATRP): Demonstration of a "Click Reaction" in Thermoreversible Property

Tailor-made ABA triblock copolymers (poly(furfuryl methacrylate)-b-poly(2-ethylhexyl acrylate)-b-poly(furfuryl methacrylate) (FEF) bearing a reactive pendant furfuryl group were successfully synthesized by atom transfer radical polymerization. The chemical compositions were calculated by H-1 NMR, and molecular weights and molecular weight distributions were determined by gel permeation chromatography analysis. The tensile properties of the triblock copolymers such as tensile strength, elongation at break, and tension set were studied. Differential scanning calorimetry (DSC) analysis and dynamic mechanical analysis (DMA) show the existence of two glass transition temperatures (T-g) and thereby the presence of well-defined soft and hard phase. Thermoreversible self-healing material was successfully prepared by using Diels-Alder reaction between this reactive furfuryl group (diene) of the A BA triblock copolymer and a bismaleimide (dienophile). Thermoreversible property of the polymer was confirmed by FTIR and DSC analysis. The self-healing nature of the polymers was characterized by scanning electronic microscopic analysis. Viscoelastic behavior of the Diels-Alder polymer was thoroughly studied by DMA studies.