Accessible Requires Authentication Published by De Gruyter December 13, 2011

Effect of lignin and hemicelluloses on the tensile strength of micro-veneers determined at finite span and zero span

André Klüppel and Carsten Mai
From the journal

Abstract

Scots pine micro-veneers were subjected to hydrolysis with sulphuric acid or delignification with acidic sodium chlorite and a combination of both treatments. The tensile strength of untreated and treated veneers was determined at finite span (f-strength) and zero span (z-strength) under both dry (20°C, 65% relative humidity) and water-saturated conditions. Acidic hydrolysis resulted in significant strength losses in both testing modes and both moisture conditions, with the greatest strength reduction found for f-strength tested dry. After delignification, only f-strength under wet conditions was substantially reduced; dry f-strength and both dry and wet z-strength hardly changed. A combined treatment of prehydrolysis and delignification resulted in disintegration of the veneers, which made strength determination impossible. It was concluded that, in addition to cellulose, the hemicelluloses determine the f-strength under dry conditions, while lignin confers wet strength but appears not to contribute to interfibre adhesion and f-strength under dry conditions.


Corresponding author. Wood Biology and Wood Products, Burckhardt-Institute, Georg August University of Göttingen, Büsgenweg 4, 37077 Göttingen, Germany Phone: +49-551-3919807 Fax: +49-551-399646

Received: 2011-7-22
Accepted: 2011-11-1
Published Online: 2011-12-13
Published in Print: 2012-05-01

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