Influence of cellulose II polymorph nanowhiskers on bio-based nanocomposite film from Jatropha oil polyurethane

Green polyurethane from plant oil-based such as Jatropha oil has recently received attention due to its environmental friendliness and sustainability. With incorporation of nanocellulose even though at low loadings in polymer matrices has shown a significant improvement. However, limited research has been done on different cellulose nanowhisker (CNW) polymorphs and their impact on composites. A number of studies have shown that the handling of cellulose polymorph also improves the properties of composite products as the cellulose II is more chemically reactive and thermodynamically stable than cellulose I. The aim this study is to investigate the effect of CNW with cellulose II polymorph in Jatropha oil-based polyurethane (JOPU). Different weight percent of CNW-II (0.1-1.5 wt%) were incorporated into JOPU films using vacuum rotavap and film casting. The total weight of 6 g was used as a fixed ratio (1:3) matrix of 4.4'-diphenyl-methane diisocyanate (MDI) and Jatropha-oil polyol (JO). The acid hydrolysis process was subjected to mercerised microcrystalline cellulose (MMCC) for the production of CNW-II. X-ray diffraction analyses were carried out to confirm cellulose II lattice of CNW-II. The CNW-II morphology was analysed using the transmission electron microscope. It was found that CNW-II had a granule-like shape with an average size of 74.04 nm in length and 21.36 nm in width. The translucency and colour of the film have also been tested by optical light microscopes. The clarity of the film and colour found affected by the highest CNW-II film loading. Based on the FTIR analysis, the spectra of all films show a typical polyurethane pattern that JOPU spectra found dominant due to very low volume NCW-II content in film. The same trend is observed for thermal degradation tested using a thermogravimetric analyser. Tensile strength and water uptake have been shown to increase in proportion to the CNW-II content.

Automated summary

This study aims to investigate the effect of cellulose II polymorph on Jatropha oil-based polyurethane (JOPU), by incorporating different weight percentages of CNW-II into JOPU films. The morphology of CNW-II was found to be granule-like, with a significant increase in tensile strength and water uptake proportional to the CNW-II content. Additionally, FTIR analysis and thermal degradation tests confirmed the dominance of JOPU spectra and similar trends in all films, respectively.