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                                       Details for article 8 of 37 found articles
 
 
  CHEMICAL CHARACTERIZATION OF PULP COMPONENTS IN UNBLEACHED SOFTWOOD KRAFT FIBERS RECYCLED WITH THE ASSISTANCE OF A LACCASE/HBT SYSTEM
 
 
Title: CHEMICAL CHARACTERIZATION OF PULP COMPONENTS IN UNBLEACHED SOFTWOOD KRAFT FIBERS RECYCLED WITH THE ASSISTANCE OF A LACCASE/HBT SYSTEM
Author: Thiago Alessandre da Silva
Paulina Mocchiutti
Miguel A. Zanuttini
Luiz Pereira Ramos
Appeared in: BioResources
Paging: Volume 2 (2007) nr. 4 pages 616-629
Year: 2007
Contents: Oxidative treatments, without and with assistance of a Laccase-Mediator System (LMS), were characterized in relation to their effects on the chemical composition and strength properties of the fibrous fraction of an unbleached recycled softwood kraft pulp. The LMS, composed of a Trametes hirsuta laccase extract and 1-hydroxybenzotriazole (HBT), was applied on the fibrous fraction of a recycled pulp at low consistency under continuous stirring and oxygen bubbling. Control treatments adding neither the enzyme nor the mediator were also considered. The LMS treatment caused a partial reversion of the detrimental effects of hornification. A considerable increase in the amount of carbonyl groups on the lignin structure was observed as a result of the enzyme treatment. The amount of extractives in ethanol:toluene also increased after the enzymatic treatment, and the dioxane-soluble kraft lignin underwent a noticeable decrease in its apparent molecular mass. This latter effect was readily attributed to the hydrolysis of aryl-ether bonds that survived the severity employed in the pulping process. These observations were useful to explain why LMS-recycled fibers produce handsheets with 9.4% better tensile strength than the control pulps.
Publisher: College of Natural Resources, North Carolina State University
Source file: Elektronische Wetenschappelijke Tijdschriften
 
 

                             Details for article 8 of 37 found articles
 
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