Process Biochemistry, Vol.102, 82-91, 2021
Insight into the in-situ solvent-free lipase-catalyzed coating on cotton with polyesters
In-situ solvent-free lipase-catalyzed coating on cotton with polyesters was optimized using the orthogonal experiment design. Lipase from Thermomycel lanuginosus (TLL) was used directly without any treatment. Enzyme loading, reaction time and temperature were chosen as factors, and water contact angle (WCA) as the index. When reactions were performed at 40 degrees C for 9 h with 45 % v/v of lipase in water bath, the optimal WCA of 119.6 degrees was achieved. NMR, MALDI-TOF mass spectra and FTIR spectra proved the chemical linkage of poly(ethylene glutarate) onto C6 from cotton. The physical properties of cotton were not much affected during the modification due to its mild conditions. Furthermore, in-situ enzymatic synthesis of poly(propylene glutarate) gave better hydrophobicity with an increase of 7.86 % in WCA compared with different substrates. Ultrasound pretreatment and vacuum significantly improved the enzymatic modification. In-situ lipase-catalyzed synthesis of poly(propylene glutarate) on cotton cellulose with ultrasound pretreatment (30 degrees C for 15 min at 120 W) and vacuum (35 degrees C for 9 h), gave the best WCA of 140.4 degrees and wetting time of 972 s. The investigation on the application of solvent-free lipase-catalyzed polymerization on hydrophobic modification of cotton cellulose provides a novel and optimal approach for the environmental friendly modification process.