Isolation and characterization of cellulose nanowhiskers from oil palm biomass microcrystalline cellulose

•CNW was successfully isolated by chemical and hydrolysis treatment.•FT-IR analysis showed that there are no significant changes in the peak positions.•SEM revealed that the aggregated structure of MCC is broken down after treatments.•TEM displayed nanoscale structure of CNW produced.•The CNW produced shown to have a good thermal stability. The objective of this study is to compare the effect of two different isolation techniques on the physico-chemical and thermal properties of cellulose nanowhiskers (CNW) from oil palm biomass obtained microcrystalline cellulose (MCC). Fourier transform infrared analysis showed that there are no significant changes in the peak positions, suggesting that the treatments did not affect the chemical structure of the cellulose fragment. Scanning electron microscopy showed that the aggregated structure of MCC is broken down after treatment. Transmission electron microscopy revealed that the produced CNW displayed a nanoscale structure. X-ray diffraction analysis indicated that chemical swelling improves the crystallinity of MCC while maintaining the cellulose I structure. Acid hydrolysis however reduced the crystallinity of MCC and displayed the coexistence of cellulose I and II allomorphs. The produced CNW is shown to have a good thermal stability and hence is suitable for a range of applications such as green biodegradable nanocomposites reinforced with CNW.