Effect of nanofibrillated cellulose made from enzyme-pretreated bamboo pulp on paper strength

Abstract

The applicability of bleached bamboo kraft pulp (Ba-BKP) was explored as a raw material for the manufacture of nanofibrillated cellulose (EN-NFC) made of enzyme-pretreated pulps and the effects of the EN-NFC on enhancing paper strength. The Ba-BKP was pretreated using an endo-glucanase enzyme at 50 °C and pH 6, after which the EN-NFC was made by micro-grinding. Bleached hardwood kraft pulp (Hw-BKP) was used as a control, and the non-enzymatic refining pretreatment of BKPs was compared with the enzyme pretreatment. The EN-NFC was incorporated into handsheets, and the sheet strengths were measured. The physical properties of the NFC made from the Ba-BKP were similar to those made from the Hw-BKP. The NFC prepared following enzyme pretreatment were smaller and more uniform than those pretreated with refining. The EN-NFC made from the Ba-BKP was effective at enhancing tensile index by 52.7%, and burst index by 210.2% when 2% of EN-NFC was added in the furnish, and those of handsheets containing the EN-NFC made from Hw-BKP showed the similar improvement. Therefore, Ba-BKP can be used as a raw material for the manufacture of EN-NFC that confers similar physical properties and strength enhancement to paper as those made from Hw-BKP.