Surface Modification of Cellulose Fibers with Hydrolases and Kinases

10.4 Conclusions

Hydrolases and kinases based enzymatic processes, performed at mild to the cellulose fibers conditions—neutral pH and moderate temperature were efficient to restore the tensile strength of resins cross-linked cellulose fibers and to introduce new phosphate functional groups in fiber structure.

The protease hydrolysis of the amide bond in N-hydroxymethyl acryl amide cross-linked cellulose resulted in about 15% strength loss recovery coupled with up to 8% decrease of the crease-resistance effect. The lipase treatment of BTCA cross-linked cotton fabrics improved the tensile strength with up to 10%, causing just 4% deterioration of the wrinkle-resistance. Data from FT-IR spectroscopy confirmed the occurrence of protease and lipase catalyzed hydrolysis registering a decrease of the intensity of the amide and carboxyl carbonyl peaks in enzymatically treated samples. The size of the enzymes and related steric difficulties to form the enzyme-substrate intermediate complex restricted the process on fiber surface preventing further undesirable cross-links removal. In contrast, in the conventional alkaline hydrolysis the deterioration of the wrinkle-resistance of the fabrics predominates on the recovery of the strength loss.

Cotton cellulose was enzymatically phosphorylated in a new biosynthetic process using hexokinase in the presence of phosphoryl donor ATP. An innovative enzymatic analytical approach, originally developed for determination of G-6-PDH, was used to detect the occurrence of phosphate functional modification of cellulose. Phosphorylation of 0.03% of the glucopyranose units in the cellulose fibers provided a textile material with improved dyeability and flame-resistance, which additionally might be used for large number of chemical synthesis.