Photo-responsive liquid crystalline polymer from a renewable furfural derivative of dimethyl 2,5-furandicarboxylate via catalytic carbonylative esterification

Transformation of bulky biomass into a carbon source for the chemical industry is important as it can provide different monomers for the syntheses of high-performance and/or functional polymers. In this work, Pd-catalyzed carbonylative esterification of methyl 5-bromofuroate, derived from renewable furfural, to dimethyl 2,5-furandicarboxylate (DMFD) has been explored under mild conditions with CO as the reductant source. The prepared DMFD was then used as a bi-functionalized monomer for the synthesis of a photo-responsive liquid crystalline polymer (PAzo-DMFD) through melt polycondensation. This furan-based polyester PAzo-DMFD shows excellent thermal stability and reversible trans–cis photo-isomerization in chloroform solution and in thin films benefitting from the azobenzene unit along the polymeric backbone. Photoisomerization of PAzo-DMFD can be used in the writing and erasing of information under light irradiation, thus providing new opportunities for the syntheses and applications of functional furan-based polymers.