Controlled preparation of cellulose acetate by deep eutectic solvent homogeneous catalysis

Area of Science:

• Materials Science
• Polymer Chemistry
• Green Chemistry

Background:

• Cellulose acetate is a versatile biopolymer with numerous applications.
• Traditional cellulose acetate preparation methods often involve harsh chemicals and complex procedures.
• Developing environmentally friendly and efficient synthesis routes is crucial.

Purpose of the Study:

• To propose a homogeneous preparation strategy for cellulose acetate.
• To utilize a novel deep eutectic solvent (DES) for cellulose dissolution and acetylation.
• To investigate the influence of reaction parameters on the degree of substitution (DS).

Main Methods:

• Homogeneous dissolution of bamboo pulp using a specific DES (ZnCl2/PA/H2O, 1:1:3 molar ratio).
• Acetylation of dissolved cellulose using acetic anhydride (Ac2O).
• Analysis of cellulose acetate properties, including degree of substitution and substituent distribution.

Main Results:

• The DES demonstrated good solubility for high-degree-of-polymerization bamboo pulp.
• Cellulose transformed from crystalline type I to type II after regeneration.
• Cellulose acetate with a DS ranging from 0.42 to 1.81 was successfully synthesized.
• Substituent distribution was found to be C-6 > C-2 > C-3.

Conclusions:

• A simplified, catalyst-free, and greener method for homogeneous cellulose acetate preparation was established.
• The developed DES system offers an efficient route for cellulose dissolution and acetylation.
• This study provides a new perspective for sustainable cellulose derivative synthesis.