Bio-based polyamides (100%) with responsive functionality were designed and synthesized by using biorenewable diamine and dicarboxylate. 1,5-Pentanediamine and dimethyl furan-2,5-dicarboxylate were chosen not only because of the biomass feedstock but also because of the reactivity of the furan rings. Enzymatic process enhanced the sustainability of these 100% bio-based furan-containing polyamides (PA5F). By regulating the temperature, PA5F was cross-linked at a low temperature via the Diels−Alder (DA) reaction and then was de-cross-linked at a high temperature. Alternatively, ultrasound exhibited a better performance in triggering the transformation of cross-linked polymers back to the original ones. The DA linkage could also be solidified by aromatization. The thermal properties were well controlled by reversible cross-linking. These 100% bio-based polyamides would open the window for the development of smart sustainable polymers with broad applications.
Photoinduced Cu(II)-mediated reversible deactivation radical polymerization (RDRP) was employed to synthesize poly(vinylidene fluoride-co-chlorotrifluoroethylene)-graft-polyacrylonitrile (P(VDF-co-CTFE)-g-PAN). The concentration of copper catalyst (CuCl 2 ) loading was as low as 1/64 equivalent to chlorine atom in the presence of Me 6 -Tren under UV irradiation. The light-responsive nature of graft polymerization was confirmed by "off-on" impulsive irradiation experiments. Temporal control of the polymerization process and varied graft contents were achieved via this photoinduced Cu(II)-mediated RDRP.
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