Amphoteric polymers to improve paper dry strength


  • Deusanilde de Jesus Silva Universidade Federal de Viçosa
  • Song Won Park Polytechnic School University of São Paulo
  • Martin Allen Hubbe NC State University



Nanotechnology, Polyampholytes, Paper strength, Surface charge density, Electrostatic interaction, Colloidal chemistry


The objective of the present work is to evaluate the application of an amphoteric polymer, with acidic and basic groups on the polymer chain, as a paper dry strength additive. The polymer studied here is random terpolymer of high electrostatic charge density, and high molecular weight. The results of our work showed that the balance between the charge densities of the surface and the polymer structures is an important factor to be considered when using this polymer. The highest paper strength value, measured by tensile index, was found at the polyampholyte’s isoelectric point (ca. pH of 7.3) when the charge of the fiber surface was negative and the polymer structure charge was symmetric. This observation agrees with our dynamic light scattering results which, demonstrated that at the isoelectric point there was a maximum in association among polyampholyte molecules, leading to a maximum in size of molecular aggregates. When adsorbed on an electrically charged surface, the maximum amount of adsorbed polymer, measured by the shift in resonance frequency in a quartz crystal microgravimetric balance, was observed for the same isoelectric point. Better results for paper dry strength were found when the fiber surface and the polymer structures were oppositely charged or at the isoelectric point of the polymer. Less effective addition strategies were found in the case when the fiber surfaces and the polymer structures had same sign of charge.

DOI: 2446941601022015065


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Author Biographies

Deusanilde de Jesus Silva, Universidade Federal de Viçosa

Engenheira Química com especialização, mestrado e doutorado na área de celulose e papel. Trabalhou para empresas do setor e fornecedora de produtos químicos. Atualmente, é professora adjunto para o curso de Engenharia Química da UFV atuando nas áreas de nanotecnologia, biorrefinaria e matérias-prima e produtos de fontes renováveis.

Song Won Park, Polytechnic School University of São Paulo

Possui graduação em Engenharia Química pela Universidade de São Paulo (1980), mestrado em Engenharia Química pela Universidade de São Paulo (1987) e doutorado em Engenharia Química pela Universidade de São Paulo (1995). Atualmente é professor assistente doutor da Universidade de São Paulo. Tem experiência na área de Engenharia Química, com ênfase em Controle de Processos Químicos, atuando principalmente nos seguintes temas:processamento de material lignocelulósico, celulose e papel, controle de processos, fabricação de papel e máquina de papel.

Martin Allen Hubbe, NC State University

Dr. Martin A. Hubbe, Professor, and Buckman Distinguished Scientist, focuses on chemical additives to the paper machine, including the colloidal chemistry affecting dewatering, the charged nature of cellulosic materials and the development of dry strength.

Dr. Hubbe has an M.S. degree from the Institute of Paper Chemistry and a Ph.D. in colloidal chemistry from Clarkson University. His teaching is primarily related to paper machine wet-end and colloidal chemistry.

Dr. Hubbe is a member of TAPPI, where he has chaired short-courses and earned a Division Award for service. Together with Dr. Lucian Lucia, he is also founding co-editor of the online peer-reviewed journal BioResources. Recent research has been aimed at mechanisms underlying the use of polyampholytes as dry-strength additives, and a reinterpretation of the nanoporosity and charge characteristics of cellulosic fibers, including their interactions with cationic polyelectrolytes.


Professor of Biobased Materials, Aalto University (Finland)
Professor of Forest Biomaterials and Chemical and Biomolecular Engineering, NC State University
2013-2017 NC State Faculty Scholar
Finland Distinguish Professor, Aalto Universty
Past Chair, Division of Cellulose & Renewable Materials, American Chemical Society



How to Cite

Silva, D. de J., Park, S. W., Hubbe, M. A., & Rojas, O. J. (2015). Amphoteric polymers to improve paper dry strength. The Journal of Engineering and Exact Sciences, 1(2), 65–79.



Engineering Materials and Nanotechnology

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