Enzyme-Assisted Preparation of Fibrillated Cellulose Fibers and Its Effect on Physical and Mechanical Properties of Paper Sheet Composites

Abstract

The fabrication of fibrillated cellulose fibers and their utilization have been of more interest recently because of their biodegradability, low cost, and mechanical and thermal properties comparable to those of glass fibers or carbon fibers. In this study, we applied the combination of a mechanical shearing process with a cooling system and an enzymatic pretreatment to produce fibrillated cellulose fibers from softwood pulps. The effects of the mechanical shearing process, the cooling system, and the enzymatic treatment on the formation of the fibrillated cellulose fibers as well as physical and mechanical properties of paper were investigated. It was indicated that the cooling system was necessary in the grinding process to prevent the adverse effect of heat generation on mechanical properties of paper sheets. It was observed that the enzyme-assisted mechanical shearing process improves the production of fibrillated cellulose fibers and results in a substantial improvement of tensile strength and elongation of paper while producing thinner and less bright paper with low water absorptiveness.

The feasibility of incorporating cellulose micro/nanofibers in papermaking processes: the relevance of enzymatic hydrolysis

“…However, the enzyme used in the present work suffers its denaturation at 80°C (Henriksson et al 2007;Pääkkö et al 2007;Yoo and Hsieh 2010). In this sense, taking the operating conditions of treatment 4 and increasing the temperature to 10°C, the resulting breaking length increase was 69 %, being lower than that achieved at 50°C.…”

“…In any case, the enzyme dosage required to enzymatically hydrolyze cellulose with the purpose of producing CNF is quite controversial. In this sense, some researchers decided to apply from 200 to 30,000 g/ton of enzymes to the pulp slurry (Henriksson et al 2007;Sehaqui et al 2011aSehaqui et al , 2013; others decided to apply the lower dosage from the above-mentioned literature (Yoo and Hsieh 2010), and those who were more moderate decided to establish an enzyme charge of 80 g/ton (Pääkkö et al 2007;Charani et al 2013a, b;Petroudy et al 2014). This was reflected in the property enhancement that the CNFs produced in the above-mentioned literature were able to provide to the paper that they produced.…”

Functionalized Polymers from Lignocellulosic Biomass: State of the Art

“…MFCs are typically produced by one of four mechanical methods: homogenization, microfluidization, microgrinding, or cryo-crushing, which consume different amounts of energy. Cooling during grinding was deemed necessary to prevent the adverse effect of heat generation on the mechanical properties of MFC for the production of paper sheets [65]. The addition of a cooling system enables the stabilization of temperature preventing thermal degradation of fibers.…”

“…Different enzymes, such as cellulase prepared from Aspergillus spp. [65], xylanases [71], and endoglucanases [72] have been used in pretreatments. Moreover, while HCl-hydrolyzed MFC from wood showed an uneven distribution of fiber geometry and a large extent of thick cell wall fragments of low aspect ratio, the MFC produced from endoglucanase-pretreated cellulosic fibers showed higher average molar mass and larger aspect ratio [72].…”

Consolidation and dewatering of a microfibrillated cellulose fiber composite paper in wet pressing

“…Because nanofibers are notably smaller than typical pulp fibers, excellent surface-and optical properties can be achieved [5,6]. Since the surface area is large, the bonding efficiency of the nanofibers leads to good strength properties [7][8][9][10][11][12][13]. While numerous laboratory studies have explored the properties of nanocellulose papers and composite materials, comparatively slight attention has been focused on feasible, large scale manufacturing routes.…”