Synthesis and crystallization of new fully renewable resources-based copolyesters: Poly(1,4-cyclohexanedimethanol-co-isosorbide 2,5-furandicarboxylate)

Abstract

In this paper, a series of fully biobased poly(1,4-cyclohexanedimethanol-co-isosorbide 2,5-furandicarboxylate)s (PCIsFs) copolyesters have been synthesized from dimethyl-2,5-furandicarboxylate (DMFD), isosorbide (IS) and 1,4-cyclohexanedimethanol (CHDM) by melt polycondensation. The structure of prepared polymers was characterized by 1H NMR and FTIR spectroscopies. Differential scanning calorimetry (DSC) results indicated that the crystallizability and melting temperature (Tm) of PCIsFs can be controlled with the increasing content of isosorbide furanoate units into the copolyesters structure, whereas their glass transition temperatures (Tg) showed a beneficial increase ranging from 76.8 °C to 103.5 °C. Wide-Angle X-ray Diffractometry (WAXD) patterns revealed that a small portion of isosorbide units are inserted into the crystals of PCHDMF, resulting in increase of the interplanar distances and crystal defects. A banded spherulitic morphology was observed, while coarsening of spherulites and increase in band distance occurred with increasing isosorbide content. Thermogravimetric analysis (TGA) results showed an excellent thermal stability up to 360 °C for all copolymers.