Alkaline treatment of diacetate fibers and subsequent cellulase degradation

Abstract

The work investigated the degradation behavior of cellulose acetate (CA) fibers in NaOH solutions in heterogeneous conditions and the effect of alkaline treatment on cellulase degradation of CA fibers. Weight analysis and IR spectra showed that the weight loss of CA fibers immersed in NaOH solution chiefly depended on acetylation. Alkaline treatment promoted the degradation of CA fibers in cellulase solution by reason of deacetylation, especially when the degree of substitution (DS) of CA fibers reached 0.8, cellulase degradation increased most markedly. SEM revealed a smooth surface except some thin holes in the CA fibers after immersion in NaOH solution with a lower concentration because of the formation of alkaline cellulose, and only in a higher concentration such as 5.0N, it could be observed that microfibers perpendicular to fiber axis distributed over the surfaces of the fibers. 1 NMR spectra suggested that only in a lower NaOH concentration ( 0.25N), deacetylation reaction was affected by the reactivities of ester groups at position 2, 3, and 6 in anhydroglucose unit, but did not follow the theoretical trend in the three positions. Moreover, the DS for polymer molecules in CA fibers were dispersive after alkaline treatment in heterogeneous condition and the DS of the product increased during sequent cellulase degradation. This was also demonstrated by the result of IR analysis and Xray diffraction.

Deacetylation Processing of Waste Cigarette Butts for High-Titer Bioethanol Production toward a Clean Recycling Process

“…The deacetylation processes greatly enriched the cellulose compo-nent that could be used for glucose production. 39 The cellulose content in pristine WCBs was only 54.94%, which was increased to 76.67−94.61% after deacetylation. It appeared that the higher deacetylation ability of the solvent system selected correlated well with the resulting higher cellulose content.…”

“…The NaOH-OS, NaOH-60 °C, and NaOH-100 °C solvent systems showed a comparatively high deacetylation ability, which was consistent with the results of FTIR assessment. The deacetylation processes greatly enriched the cellulose component that could be used for glucose production . The cellulose content in pristine WCBs was only 54.94%, which was increased to 76.67–94.61% after deacetylation.…”

Are we overestimating the permanence of cellulose triacetate cinematographic films? A mathematical model for the vinegar syndrome

“…First order in acetyl concentration: Deacetylation of CTA in solution shows a first-order dependence on degree of substitution (35). It is known that the reactivity of acetyl groups varies with the carbon position, and this appears to affect the order in which they react, although this depends on the particular reaction conditions (36)(37)(38)(39)(40)(41)(42). In industrial processes, CTA is partially hydrolysed to yield different grades of CA, which may contain different distributions of acetylated carbons (27).…”

Thermo-responsive poly(N-isopropylacrylamide)-grafted hollow fiber membranes for osteoblasts culture and non-invasive harvest

“…The purpose of alkaline treatment is to achieve the deacetylation of cellulose acetate [17,18], and to form the hydroxyl, which can be oxidized by CAN and produce free radicals. As an initiator, CAN leads to formation of free radicals during oxidation of C2 and C3 hydroxyl groups of anhydro-Dglucose of cellulose, which then initiates the graft polymerization of NIPAAm vinyl monomer ( Fig.…”