Use este identificador para citar ou linkar para este item: https://locus.ufv.br//handle/123456789/14083
Tipo: Artigo
Título: Amphoteric polymers to improve paper dry strength
Autor(es): Silva, Deusanilde de Jesus
Park, Song Won
Hubbe, Martin Allen
Rojas, Orlando José
Abstract: 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.
Palavras-chave: Nanotechnology
Polyampholytes
Paper strength
Surface charge density
Electrostatic interaction
Colloidal chemistry
Editor: Revista de Engenharia Química e Química
Tipo de Acesso: Open Access
URI: http://www.seer.ufv.br/seer/rbeq2/index.php/req2/article/view/54
http://www.locus.ufv.br/handle/123456789/14083
Data do documento: 1-Dez-2015
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