ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 2, pp. 339!341. + Pleiades Publishing, Inc., 2006.
Original Russian Text + O. S. Beusheva, N. P. Mus’ko, M. M. Chemeris, 2006, published in Zhurnal Prikladnoi Khimii, 2006, Vol. 79, No. 2,
The Role of Readily Hydrolyzable Polysaccharides
of Larch Wood in Manufacture of Board Materials
O. S. Beusheva, N. P. Mus’ko, and M. M. Chemeris
Polzunov State Technical University, Barnaul, Russia
Received December 21, 2005
Abstract-Role of readily hydrolyzable polysaccharides of larch wood in production of board materials is
The problem of development of environmentally
friendly and cost-efficient board materials is now
pressing as before. The reason is that thermosetting
synthetic resins are mostly used in manufacture of
board materials as binders, in addition to a wood filler
and adhesive component, e.g., phenol-formaldehyde
It was demonstrated in [1, 2] that all components
required for production of board materials can be ob-
tained through hydrothermal treatment of wood.
An equally important problem is utilization of
large-scale waste of larch wood, which known to have
limited application in wood-chemical processing.
Therefore, we examined in this study the possibil-
ity of manufacture of board materials from larch wood
exposed to explosive autohydrolysis (EAH).
We examined the effects of temperature and pres-
sure on the behavior of readily hydrolyzable poly-
saccharides of larch wood in production of board
materials by hot pressing.
As a raw material for production of boards, we
used larch wood chips (25 0 15 0 5 mm) after extrac-
tion of bioactive components (arabinogalactan and di-
hydroquercitrin). Before exposure to explosive auto-
hydrolysis, the chips were treated with water in a 2 : 1
volume ratio . The explosive autohydrolysis was
carried out in an autoclave at 220oC for 10 min. Then
the resulting lignocarbohydrate material was air-dried,
formed into a mat, and hot pressed.
Wood is composed of a complex set of macromo-
lecular compounds, such as cellulose, hemicellulose,
and lignin, cross-linked by chemical and hydrogen
bonds and also by nonspecific physical interactions.
The explosive autohydrolysis strongly modifies the
structure of the initial material at the macro- and mi-
crolevels. Previously, we have demonstrated  that,
under hydrothermal conditions, readily hydrolyzable
polysaccharides of larch wood are hydrolyzed to give
a large amount of reducing agents (RAs). The tem-
perature of 220oC and treatment time of 10 min are
the optimal conditions for the hydrolysis, under which
the content of readily hydrolyzable polysaccharides in
the wood pulp decreases from 22.9 to 3.2%. The con-
tent of reducing agents in the resulting aqueous ex-
tract is 15.4%. The UV spectra showed that the reac-
tion mixture contains phenolic compounds . Thus,
the pulp obtained after explosive autohydrolysis of
larch wood contains components that can enter into
polycondensation reactions. It may be suggested that,
similarly to the reactions of phenols with aldehydes
yielding phenol-formaldehyde resins with liberation of
water, the p-hydroxyphenylpropane units (PPUs) of
lignin react with the aldehyde groups of sugars [6, 7].
A simplified scheme of the reaction can be written as
Lignin PPU Hexose Phenolic alcohol
where R = C