Kinetics and mechanism of nonisothermal crystallization of biobased poly(hexamethylene 2,5-furan dicarboxylate)

Abstract

Biobased poly(hexamethylene 2,5-furan dicarboxylate) (PHF) was synthesized by the two-stage melt polycondensation method (transesterification and polycondensation) in a glass batch reactor. The nonisothermal crystallization from the melt and from the glass was studied by means of Differential Scanning Calorimetry, Fast Scanning Calorimetry and advanced kinetic analysis. It is shown that changes in the crystallization regime occurs at certain temperatures and that the end of the crystallization presents some deviation from what is predicted by the Hoffman-Lauritzen's theory of growth rate. A method is presented that allows the determination of the equilibrium melting temperature, the infinite glass transition temperature, the temperature at maximum of the growth rate, and accurate simulation of crystallization rate curves. An equation is proposed for modelling the crystallization process using a methodology that avoid the problem of local minima occurring when too many parameters must be determined simultaneously.