PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL FROM THE PUBLISHERS OF PAPER TE Volume 7, Number 3, 2021
Locust bean gum adsorption onto softwood kraft pulp fibres: isotherms,
kinetics and paper strength JINGQIAN CHEN 1,2 , RODGER P. BEATSON 3 & HEATHER L. TRAJANO 1,2 .
The adsorption of locust bean gum (LBG) onto Northern Bleached Softwood Kraft (NBSK) pulp improved paper tensile and burst strength and lowered refining energy by strengthening inter-fibre bonding. Adsorption kinetics and isotherms were investigated to develop a fundamental understanding of the adsorption mechanism. The adsorption rate followed pseudo-second-order kinetics and the activation energy was 99.34 kJmol -1 , suggesting chemisorption. The adsorption rate constant increased rapidly with temperature from 25 to 45 °C (k = 1.93 to 24.03 gmg -1 min -1 ), but the amount adsorbed at equilibrium decreased (qe = 1.91 to 0.48 mgg -1 o.d. fibre). LBG adsorption to NBSK at 25 °C was consistent with the Langmuir adsorption model for LBG<2.1 wt% of o.d. fibre, suggesting reversible, homogenous adsorption to a finite number of sites on the fibre surface. Refining to 3000 rev increased the heterogeneity of the NBSK pulp surface leading to multi- layer Freundlich adsorption with adsorption constant n = 5.00, and the equilibrium constant Kf = 2.57 mgg - 1 (mgL -1 ) -1/n at 25 °C. Favorable adsorption conditions for negatively charged LBG were identified: 25 °C for 10 min, low dosage level (<2 wt%), lightly refined (<3000 rev) NBSK pulp at low fibre consistency (<0.5 wt%), high agitation rate (>150 r.p.m.), acidic or neutral conditions (pH 2 – 7) without salt addition. Contact information: 1. Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC V6T 1Z3, Canada. 2. BioProducts Institute, University of British Columbia, Vancouver, BC V6T 1Z3, Canada 3. Chemical and Environmental Technology, British Columbia Institute of Technology, 3700 Willingdon Avenue, Burnaby, BC V5G 3H2, Canada
Cellulose (2021) 28:10183 – 10201 https://doi.org/10.1007/s10570-021-04133-w Creative Commons Attribution 4.0 International License
The Paper Industry Technical Association (PITA) is an independent organisation which operates for the general benefit of its members – both individual and corporate – dedicated to promoting and improving the technical and scientific knowledge of those working in the UK pulp and paper industry. Formed in 1960, it serves the Industry, both manufacturers and suppliers, by providing a forum for members to meet and network; it organises visits, conferences and training seminars that cover all aspects of papermaking science. It also publishes the prestigious journal Paper Technology International and the PITA Annual Review , both sent free to members, and a range of other technical publications which include conference proceedings and the acclaimed Essential Guide to Aqueous Coating .
Article 1 – Locust Gum Bean & Strength
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