Poly-2-vinylfuran,synthesis, characterization,and diels-alder reaction with maleic anhydride

Poly-2-vinylfuran, synthesized by free-radical polymerization of 2-vinylfuran, was characterized by nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy. The pendant furan rings on the polymer backbone were then used as the diene component of a Diels-Alder reaction with maleic anhydride. The juxtaposition of the furan rings at first suggested an “avalanche” Diels-Alder reaction, in which the product of one cyclization would be the reactant of the next. A lack of polymer stereoregularity and the reversibility of the Diels-Alder reaction, however, prevented its formation. On the other hand, when the dienophile was used in a 1:1 molar ratio with respect to furan the smooth reaction produced a new polymer, the maleic anhydride adduct of poly-2-vinylfuran, which characterized by NMR and IR spectroscopy, was air stable and soluble in a number of solvents up to 70% transformation. When heated to 160°C the polymer reverted to maleic anhydride and somewhat decomposed poly-2-vinylfuran.