Ability of a cellobiohydrolase I+II mixture and endoglucanase of the Trichoderma reesei strain to change lyocell fibres

Lyocell fibers were treated for 24 h with two different types of cellulase enzymes, endoglucanase (EG) and a mixture of cellobiohydrolases (CBH I+II) from the Trichoderma reesei strain. After treating the fibers with 0.5 and 2 mg/g of EG and 2 mg/g of CBH, the fiber surface was damaged (observed by optical microscope), the fibers became brittle, and hence mechanical properties such as the tensile strength, elongation at break and abrasion resistance decreased. The weight loss (WL) test using 6 % NaOH alone, 4 % urea alone and their mixture showed that the WL of the fibers was not affected by the enzymatic treatments. The moisture regain, degree of polymerisation, crystallinity index, measured by ATR (attenuated total reflectance), and the FTIR of the enzyme treated fibers also did not change.