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Activating cellulose via its reversible reaction with CO2 in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene for the efficient synthesis of cellulose acetate

“…But the as-prepared samples (CA-1, CA-2) become insoluble in DMSO when the reaction times are decreased from 0.5 h to 0.17 h (10 min) and 0.08 h (5 min). It can be seen that the three hydroxyl groups at C2, C3, and C6 position exhibit different reaction activities, and the order of reactivity is C6-OH > C2-OH > C3-OH, which is similar to the acetylation of cellulose in LiCl-1,3-dimethyl-2-50 imidazolidinone (DMI) solutions 33 and CO 2 -based reversible ionic liquids. The reaction temperature has significant effect on the reaction, which was evidenced by the fact that a product with DS of 2.26 (CA-9) was obtained when the reaction was performed at 50 o C in 5 h. CA with various DS were 15 also obtained through modifying the molar ratio of acetic anhydride/AGU.…”

Synthesis and properties of biodegradable plastic films obtained by microwave-assisted cellulose acylation in homogeneous phase

“…Cellulose chemical modifications occur more easily in amorphous regions than in crystalline ones [2]. Homogeneous derivatization needs either activation [3] or solubilization [4][5][6][7][8][9][10][11][12][13][14][15] of the polymer before its modification [16,17].…”

Propylene Carbonate Based‐Organic Electrolytes for Cellulose Dissolution Processing and Derivatization

“…Therefore, there is great interest in the design of new dissolution technologies to allow homogeneous processing and derivatisation of cellulose towards a controllable facile preparation of cellulosic materials. To date, a rather limited number of solvents are available, such as cuprammonium hydroxide solution, monohydrate of N‐methyl‐N‐morpholine oxide (lyocell process), CS 2 –NaOH aqueous solution (viscose process), LiCl‐based solvents, ionic liquids, and NaOH–urea–water aqueous solution, organic bases/DMSO/CO 2 reversible system . It is well‐recognized that significant progress in cellulose dissolution technologies will promote the design and synthesis of new cellulosic materials.…”