Reversible hydrophobization and lipophobization of cellulose fibers via trifluoroacetylation.
The surface modification of cellulose fibers with trifluoroacetic anhydride (TFAA) was studied using the heterogeneous cellulose/TFAA/pyridine/toluene system. The degree of substitution (DS) of the ensuing trifluoroacetylated fibers ranged from 0.04 to 0.30. This treatment conferred a high degree of both hydrophobicity and lipophobicity on the fibers' surface, even at low DS values. Both the dispersive and the polar contributions to the surface energy were drastically reduced. However, the original cellulose hydrophilicity could be readily restored through hydrolysis, by treating the modified fibers with neutral water.
Cunha
Ana G
AG
CICECO and Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Freire
Carmen S R
CS
Silvestre
Armando J D
AJ
Neto
Carlos Pascoal
CP
Gandini
Alessandro
A
D000089:Acetic Anhydrides; D000327:Adsorption; D001672:Biocompatible Materials / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D004951:Esterification; D005463:Fluoroacetates; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D008055:Lipids / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013997:Time Factors; D014050:Toluene / Q000737:chemistry; D014269:Trifluoroacetic Acid / Q000737:chemistry; D014867:Water / Q000737:chemistry
D000089:Acetic Anhydrides; D001672:Biocompatible Materials; D005463:Fluoroacetates; D008055:Lipids; D011725:Pyridines; D014867:Water; D014050:Toluene; C017958:trifluoroacetic anhydride; D002482:Cellulose; D014269:Trifluoroacetic Acid; C023666:pyridine