Fully Bio-based Micro-cellulose Incorporated Poly(butylene 2,5-furandicarboxylate) Transparent Composites: Preparation and Characterization

Abstract

Poly(butylene 2,5-furandicarboxylate) (PBF) derived from 2,5-furandicarboxylic acid (FDCA) is an emerging bio-based alipharomatic polyester that is expected to replace its fossil-based terephthalate and naphthate homologues. PBF holds excellent gas barrier properties, but its slow rate of crystallization might restrict wider applications. To improve the rate of crystalization, it was melt-blended with crystalline micro-cellulose (CMC) to prepare a composite through twin-screw extrusion. To ensure environmental friendly conditions, neither chemicals to modify fibers nor compatibilizers to improve the filler/matrix interaction were used. Size exclusion chromatography (SEC), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD) were used to characterize the composite. It was observed that a longer blending duration (cyclic mode) leads to a greater reduction in molecular weight (Mw) in the presence of CMC, which can be avoided by using a shorter blending duration (direct mode). The mechanical properties of the composite showed an increase in Young’s modulus by approximately 23 % and 36 % with respect to reference PBF for the cyclic and direct mode respectively. It was further observed that, although the elongation at break and tensile strength has decreased, it has improved gas barrier properties. Thermal analysis shows faster nucleation of PBF in the presence of CMC with a minor effect on its thermal degradation.