Cellulose (2021) 28:10183–10201
10199
bonding. At 6000 rev and 9000 rev, the scattering coefficients are independent of LBG dosage, thus indicating there is a finite degree to which bonding can be improved. The overall trends of scattering coeffi- cient agree with the trend in tensile strength with respect to refining and LBG adsorption. Consequently, NBSK paper tensile strength enhancement is mainly due to bonding formation. Brightness decreased with increased refining and LBG dosage level (Fig. 8f). However, as the chro- mophores in the pulp are not changed and the LBG is colourless, the main reason for the decrease in brightness must be the reduction in the scattering coefficient arising from increased bonded area (Ek et al. 2009; Parsons 1941; Simmonds and Coens 1967).
solely refining. Tear index, brightness and scattering coefficient decreased, likely due to greater inter-fibre bonding. The authors acknowledge Canfor Pulp University Grants Program and the Natural Sciences and Engineering Research Council of Canada Collaborative Research & Development Grant (Grant CRDPJ 462081-13) for financial support. This research was conducted as part of the UBC BioProducts Institute portfolio administered from the University of British Columbia. Acknowledgments
Declarations
Conflicts of interest
The authors declare no competing
financial interest.
Human and animal rights This article does not contain any studies with human or animal subjects performed by any of the authors. This article is licensed under a Creative Com- mons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any med- ium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Open Access
Conclusion
Locust bean gum adsorption and its performance as a strength additive was studied. The adsorption rate followed pseudo-second-order chemisorption kinet- ics. The adsorption rate constant increased rapidly with temperature from 25 to 45 C, but the amount adsorbed at equilibrium decreased. Langmuir and Freundlich models were used to describe LBG adsorption with equal fit and both were used to gain physical insight. The maximum LBG adsorption capacity of NBSK pulp fibre was compa- rable to that of native starch to pulp. The mechanism of LBG adsorption to cellulose fibres is complex and may involve multi-layer adsorption to a finite number of sites. Refining to 3000 rev increased surface hetero- geneity of NBSK pulp as evidenced by the excellent fit of the Freundlich model. Increasing temperature from 25 to 35 C caused LBG adsorption to increase at dosage level higher than 0.5wt%. Sodium chloride addition (0–1.0 mol L - 1 ) had little effect on adsorption and adsorption increased slightly at pH 2–5. Both observations are likely due to the low negative charge density on LBG. Refining and LBG dosage increased NBSK paper tensile strength and burst strength. Tensile and burst strength plateaued when refining over 6000 rev, and strength gains were small for LBG dosage greater than 0.5 wt%. However, addition of LBG enabled a reduction in refining revolutions to achieve a target tensile strength with higher freeness compared to
References
BeMiller JN, Whistler RL (eds) (2012) Industrial gums: Polysaccharides and their derivatives. Academic Press. San Diego, California Bergmann CP, Machado FM (eds) (2015) Carbon nanomaterials as adsorbents for environmental and biological applica- tions. Springer International Publishing, New York, pp 1–105 Bhaduri SK, Ghosh IN, Sarkar ND (1995) Ramie hemicellulose as beater additive in paper making from jute-stick kraft pulp. Ind Crops Prod 4(2):79–84. https://doi.org/10.1016/ 0926-6690(95)00018-8 Blanchard G, Maunaye M, Martin G (1984) Removal of heavy metals from waters by means of natural zeolites. Water Res 18(12):1501–1507. https://doi.org/10.1016/0043- 1354(84)90124-6 Chen J, Martinez DM, Chang XF, Beatson RP, Trajano HL (2020) Evolution of Hemicellulose Molar Mass during Softwood Hydrolysis. ACS Sustain Chem Eng
123
Made with FlippingBook Online document maker