Chain Structure and Molecular Weight Dependent Mechanics of Poly(ethylene 2,5-furandicarboxylate) Compared to Poly(ethylene terephthalate)

摘要

Solution and melt viscosity relations to molecular weight were obtained for bio-based poly(ethylene 2,5-furandicarboxylate) (PEF) in comparison to poly(ethylene terephthalate) (PET). Furthermore, the rate dependent glassy state tensile properties were explored at varying molecular weights, showing ductile behavior for high molecular weight PEF at low rates. The unperturbed chain dimensions of PEF indicate similar conformational freedom to PET but lower chain packing due to the shorter bond length of 2,5-furandicarboxylic acid (FDCA), inducing a lower entanglement density as corroborated by plateau moduli measurements. The high temperature and shear rate dependence of the melt viscosity as well as the high strain rate dependence of the glassy state yield stress can be explained by this lower entanglement density, although the glassy state may furthermore be subject to chain mobility restrictions.