Acetylation of plant cellulose fiber in supercritical carbon dioxide

H3PW12O40·4H2O as an efficient catalyst for the conversion of cellulose into partially substituted cellulose acetate

“…39 The peak observed around 22 in the curve of cellulose acetate was wider than that in the XRD pattern of microcrystalline cellulose, indicating a drop in the degree of crystallinity after acetylation. 40 It also can be seen from Figure 2(c,d) that the intensity of the characteristic peaks in the XRD plots of the acetylated product decreased with increasing the degree of acetylation, further indicating the acetylation results in a drop of the degree of crystallinity. 41 This can be ascribed to the replacement of hydroxyl group by acetyl groups, which makes the break of the intramolecularly and intermolecular bonds easier.…”

Preparation of microcrystalline cellulose from rice straw under microwave irradiation

“…The XRD patterns of rice straw, alkaline treated rice straw, crude cellulose and MCC are shown in Figure . The peak around 22.3° of (200) reflection is contributed to the typical crystal lattice of cellulose I β . The shoulder peak at 16.0° of (101) reflection and a weak peak at 34.6° of (040) reflection are also assigned to the cellulose phase.…”

“…The peak around 22.38 of (200) reflection is contributed to the typical crystal lattice of cellulose I b . [35][36][37] The shoulder peak at 16.08 of (101) reflection and a weak peak at 34.68 of (040) reflection are also assigned to the cellulose phase. Figure 2(c) shows that the intensity of these characteristic peaks increase in the pattern of crude cellulose compared to that of rice straw and alkaline treated sample [ Figure 2(b)], revealing the removal of lignin and hemicellulose after alkaline and acid treatment.…”

New findings about the lipase acetylation of nanofibrillated cellulose using acetic anhydride as acyl donor

“…However, ionic liquid BMIMCl (1-n-butyl-3-methylimidazolium chloride) pre-treatment was necessary in order to facilitate the unwrapping of the structure of the polysaccharide molecule and make it accessible to the enzyme. In order to avoid long pre-treatment with hazardous chemicals, some literature can also be found on the chemical homogeneous and heterogeneous esterification of cellulose in scCO 2 using high temperatures, pressures and various chemicals' catalysts (Medina-Gonzalez, Camy, & Condoret, 2012;Nishino, Kotera, Suetsugu, Murakami, & Urushihara, 2011;Yin et al, 2007). To the best of our knowledge only Gremos et al (2012) have performed the enzymatic esterification of fibrous cellulose with vinyl laurate in moderate scCO 2 .…”