A New Way to Produce Cellobiose Carbonates Using Green Chemistry

Abstract

The preparation of cellulose derivatives using green (i.e., environmentally friendly) reagents would improve sustainability and reduce concerns arising from the use of non-green reagents. The objective of this work was to prepare cellobiose carbonate using a green reagent, dimethyl carbonate. The carbonation reaction was carried out in the presence of ethanolic potassium hydroxide solution and dimethyl carbonate for 6 h at a range of temperatures (25-70 °C). A cellobiose derivative was successfully prepared with a recovered yield of more than 70 % and characterized by FTIR and NMR spectroscopy techniques. The presence of a grafted disaccharide with a degree of substitution higher than 2 was determined by (13) C NMR analysis. The spectra of the prepared cellobiose carbonate exhibited peaks that were associated with cellulose molecules (C1 -C6 ) and corresponded to carbonate functions at around 159.4 ppm.

Efficiency of Cellulose Carbonates to Produce Cellulose Nanofibers

“…We can see that all the modifications disappear after HCl treatment: the native cellulose IR spectrum reappears. Finally, it can be presumed that the chemical modification reaction occurs at the surface and the substitutions mainly occurred at secondary alcohol functions at the C 2 and C 3 positions, as previously reported. , …”

“…While the main cellulosic structure was maintained, small significant changes can be detected. There was an increase of the signal intensities in the regions 1400–1200 and 1200–900 cm –1 , corresponding to C–O vibrations, in agreement with the presence of carbonate groups. ,,− More precisely, new weak signals appear at 830 and 701 cm –1 and can be assigned to out-of-plane and in-plane bending bands of carbonates, respectively. , The presence of the carbonate functional group is also confirmed by the shoulder signal at 1695 cm –1 corresponding to the CO (carbonate) stretching vibration.…”

“…The aim of this study is to propose a new green method to produce CNFs using environmentally friendly cellulose carbonate produced according to our previously described method. , In fact, we started with the preparation of cellulose carbonates and their characterizations by several methods. Then, the second part carried out involved the use of as-prepared cellulose carbonate to produce CNFs, which, to the best of our knowledge, has not been reported until now.…”

Characterization of composite materials based on LDPE loaded with agricultural tunisian waste

“…From this figure, the values of the melting temperatures ( T m ), i.e., 105°C, and glass transition temperatures ( T g ), i.e., −20°C, are observed to remain constant with increasing content of lignocellulosic fibers up to a mass fraction of 50%. This feature is quite interesting and useful in practice because the produced films retain their flexibility even for the highest filler loading investigated here . In addition, Table indicates that the crystallinity of the prepared composites increases slightly, i.e., it was ∼34% for the matrix compared to 36.5% for a film prepared with a 30% filler (w/w with respect to the matrix).…”

“…Using the same strategy, many cellulosic resources (date palm rachis, alfa grass, and Posidonia oceanica ) are available in Tunisia. These cellulosic resources could be classified in three types: agricultural wastes , marine biomass , and nonwood plants . These resources have been studied, and the valorization of extracted fibers has been investigated for the production of paper, green composites, and cellulose derivatives.…”