Catálogo de publicaciones - tesis
Título de Acceso Abierto
Mejora de propiedades papeleras de pulpas celulósicas lignificadas de reciclo: Aplicación de tratamientos oxidativos enzimáticos y químicos
Paulina Mocchiutti Miguel Ángel Mario Zanuttini Luiz Pereira Ramos
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Resumen/Descripción – provisto por el repositorio digital
The effects of the application of enzymatic and chemical oxidative treatments on unbleached recycled softwood kraft pulps were studied with the aim of improving their papermaking properties and extending their possibilities of application. For the enzymatic treatments, the laccase-mediator system (LMS) was used. The laccases were isolated from the Trametes hirsuta fungus and the mediator used was 1-hydroxybenzotriazole. It was found that the treatments produced a slight reduction in the kappa number in parallel to an increase in the light absorption coefficient showing the oxidative effect of the enzymes on this kind of pulps. The freeness of the whole pulp increased, but the papermaking properties were not modified or decreased. The amount of carbonyl and carboxylic acid groups in the oxidized lignin of the fibrous fraction increased and consequently the tensile strength also increased. Ozone was used for the oxidative chemical treatments, which increased the tensile strength of the whole pulp and the fibrous fraction. Nevertheless, the freeness decreased. Ozone reduced the kappa number and the amount of insoluble lignin in acid medium, indicating that the oxidized lignin was solubilized. In this work, the polyelectrolyte adsorption method, necessary to determine the content of the superficial acid groups of the cellulose fibers, was optimized. An equation was proposed that fits the experimental isotherms and allows obtaining more precise results.Palabras clave – provistas por el repositorio digital
Grupos ácidos superficiales; Lacasas; Ozono; Pulpas no blanqueadas; Propiedades papeleras; Superficial acid groups; Laccases; Ozone; Unbleached pulp; Papermaking properties
Disponibilidad
| Institución detectada | Año de publicación | Navegá | Descargá | Solicitá |
|---|---|---|---|---|
| No requiere | 2007 | Biblioteca Virtual de la Universidad Nacional del Litoral (SNRD) |
|
Información
Tipo de recurso:
tesis
Idiomas de la publicación
- español castellano
País de edición
Argentina
Fecha de publicación
2007-03-22
