Rapid assessment of wetting of natural fiber surfaces by biodegradable copolyester using spectroscopic and microscopic techniques

Abstract A biodegradable polymer, the poly(butylene adipate co‐terephthalate) (PBAT), was compounded with the microcrystalline cellulose (MCC) obtained from different sources (such as wheat stalk and rice husk powder) to prepare the polymer composites. The two components, here found to be compatible, as evidenced by the Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Further assessment of the compounded fibers with the organic solvent, the toluene, illustrated the nature of the wetting phenomena of MCC by PBAT. The SEM observation showed the wrapping of the PBAT layer onto the MCC phase after the removal of the polymer matrix. The FTIR spectrum showed the presence of the PBAT carbonyl peak on extracted fibers from the composite via solvent removal. It could be concluded that the PBAT could wet the MCC effectively in the composites suggesting the potential of enhancing their properties. Highlights A biodegradable polymer, the PBAT, melt‐mixed with plant‐based natural fiber. The fiber in composites was found to be wetted with the PBAT layer. H‐bonding between the CO group of PBAT and the OH group of fiber caused wetting. Raw, processed, and silane‐treated fibers showed similar wetting phenomena.