Claisen-type degradation mechanism of cellulose triacetate membranes in ethanol–water mixtures

• Long term ethanol exposure study of cellulose triacetate (CTA) matrices over 4 weeks.
• Elucidated degradation mechanism of CTA membranes via XPS and ATR-FTIR.
• Membrane degradation proceeded via a classical Claisen-type and water condensations.
• Formation of the acetoacetate and ether pendant groups on the CTA backbone.
• Consequence of membrane degradation leads to loss of membrane stability and performance.

This work reports for the first time the degradation mechanism of cellulose triacetate membranes exposed to ethanol–water mixtures. The process of membrane degradation is elucidated by XPS, ATR-FTIR, NMR to proceed via a classical Claisen-type condensation followed by water condensation reactions leading to the formation of the acetoacetate and ether pendant groups in the polymeric matrix. This work provides vital insight into the chemical stability and durability of the cellulose ester-based membranes for long term operation in liquid separation applications involving ethanol solutions.

Ethanol degradation of cellulose triacetate membranes undergo a classical Claisen condensation and water condensation to become acetoacetate and ether pendant functionalitiesFigure optionsDownload high-quality image (93 K)Download as PowerPoint slide