Modification of cellulose degree of polymerization by superheated steam treatment for versatile properties of cellulose nanofibril film

Abstract

Cellulose from oil palm empty fruit bunch (OPEFB) was subjected to superheated steam (SHS) treatment at 150 °C for 1 and 2 h to produce cellulose with different degree of polymerization (DP). The treated OPEFB cellulose was subjected to a wet disc milling process to produce cellulose nanofibrils (CNFs), followed by nanocellulose film production using castingevaporation technique. Reduction of DP by 23 and 40% were recorded after SHS treatment of OPEFB cellulose for 1 h (SHS1) and 2 h (SHS2), respectively, as compared to the untreated OPEFB cellulose. CNFs produced from treated cellulose (CNF-SHS1 and CNF-SHS2) exhibited smaller diameter and were less entangled compared to CNF from untreated cellulose (CNF-UT). These contributed to smoother CNF-SHS films. The highest light transmittance was recorded for CNF-SHS2 film, followed by CNF-SHS1 and CNF-UT films. The increment in transmittance value is in accordance with the reduction in cellulose DP. Lower DP also caused CNF-SHS films to have less wetting property as a result of smoother film surface. Mechanical properties were affected by DP values suggesting the possibility to control mechanical properties of CNF films in relation to DP. Overall, SHS is an efficient treatment method to reduce cellulose DP with the advantage of controlling CNF film properties towards the production of a versatile CNF film.

Greener Pretreatment Approaches for the Valorisation of Natural Fibre Biomass into Bioproducts

“…Superheated steam has been managed to alter the chemical composition of natural fibres. It has been proven that superheated steam pretreatment managed to remove high amount of hemicellulose from the lignocellulose fibres [34][35][36][37][38][39][40]. According to Warid et al [40], superheated steam pretreatment on oil palm biomass at higher temperature and shorter time managed to remove a high amount of hemicellulose while maintaining the cellulose composition as compared to the method reported by Norrrahim et al [39].…”

Fabrication of regenerated cellulose fibers using phosphoric acid plus hydrogen peroxide treated wheat straw in DMAc/LiCl solvent system

“…Cellulose's degree of polymerization (DP) was measured using an Ubbelohde viscometer (Type 0.8-0.9, Loikaw, China). The condition of viscometer analysis followed the standard method ISO 5351 and calculated the DP with the Nark-Houwink equation (Megashah et al, 2020):…”

Extraction and surface modification of cellulose fibers and its reinforcement in starch-based film for packaging composites

“…3). Wettability is the ability to withhold liquid on the surface of the composite lms, which also determines the hydrophilicity properties of the lms (Megashah et al 2020). Cellulosebased coating lms have the ability to absorb moisture and swell at relatively high humidity that in uence the barrier performance as packaging materials (Nuruddin et al 2021).…”

“…Hence, the hydrophobicity properties of cellulose need to be improved through chemicals or composites (Balasubramaniam et al 2020). Chemicals such as sulfuric acid and alkali were used for surface modi cation of cellulose (Zainal et al 2019;Megashah et al 2020). Later, the use of 2,2,6,6tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation showed promising results in modifying the cellulose surface as the TEMPO-oxidized cellulose bers (TOCF) introduces negatively-charged carboxyl groups on the surface of the cellulose and form homogeneous TOCF suspensions stabilized with surface charge (Qu et al 2021).…”