Nucleation and crystallization of poly(propylene 2,5-furan dicarboxylate) by direct blending of microcrystalline cellulose: improved tensile and barrier properties

Poly(propylene 2,5-furan dicarboxylate) (PPF) is an example of alipharomatic bio-based polyester which has a high potential for the replacement of its fossil-based terephthalate counterparts (PPT). PPF offers advantages over PPT owing to its brilliant properties. However, PPF often exhibits a slow rate of crystallization, which is a bottleneck for its successful synthesis. This has also caused limited research work on the use of PPF for the specific application. Therefore, in this study, PPF is melt compounded with microcrystalline cellulose (MCC) via twin-screw extrusion, which in turn enhances its crystallization. During its preparation, no toxic chemicals are used to modify the fibers or compatibilizers, indicating that the synthesis method follows green chemistry principles. The influence of the MCC on the thermal, structure and surface behaviors of PPF is analyzed using Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry (DSC), thermo-gravimetric analysis and X-ray diffraction. The effect of the MCC on both non-isothermal and isothermal crystallization of PPF is also explored by using DSC. It is observed that crystallization is faster, while PPF is compounded with lower content of MCC. Similarly, the nucleating rate is intensified with the introduction of MCC. The incorporation of MCC significantly increased tensile modulus, strength and elongation of break of progressing PPF by 16%, 63% and 61%, respectively, at a content of 15 wt.% MCC. The blend also owned better oxygen and carbon dioxide barrier properties than neat PPF as a function of MCC content. This study is expected to spur further work on the synthesis of PPF composite for packaging applications.