Furan-based polyesters from renewable resources: Crystallization and thermal degradation behavior of poly(hexamethylene 2,5-furan-dicarboxylate)

In the present study poly(hexamethylene 2,5-furan dicarboxylate) (PHF), a polyester prepared from monomers derived from renewable resources, was synthesized by applying the melt polycondensation method. The polymer exhibited a melting temperature of about 145 degrees C while the glass transition temperature was 7 degrees C. After isothermal crystallization, PHF showed multiple melting behavior which was attributed to partial melting-recrystallization and final melting. The equilibrium melting temperature of the polymer was found to be 157 degrees C, while the heat of fusion of the purely crystalline material was found to be 34 kJ/mol (143 J/g). A crystallization regime I to regime II transition was observed at 134 degrees C as a breakpoint in the Lauritzen-Hoffman plot. The K-gI and K-gII values were calculated 0.9 x 10(5) and 1.76 x 10(5) respectively. Polarized optical microscopy was also employed for the study of the isothermal crystallization of PHF. PHF can be regarded thermally stable since its decomposition starts above 350 degrees C. Thermal degradation kinetics were investigated by means of thermogravimetric analysis. (C) 2014 Elsevier Ltd. All rights reserved.