1070-4272/05/7804-0667 + 2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 4, 2005, pp. 667!669. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 4, 2005,
Original Russian Text Copyright + 2005 by Glazkov, Biryukova.
AND POLYMERIC MATERIALS
Simulation of Wood Impregnation with Oligomer Solutions
S. S. Glazkov and I. P. Biryukova
Voronezh State Academy of Forestry Engineering, Voronezh, Russia
Received January 26, 2004; in final form, February 2005
Abstract-An adequate model is developed for the impregnant distribution along the fibers of a small-
dimension crosscut end under conditions of isothermal diffusion impregnation with oligomer solutions.
Synthetic materials are widely used for modifica-
tion of wood and wooden articles [1, 2]. The proper-
ties of the resulting material are controlled by the na-
ture of wood, type and content of impregnant, impreg-
nant distribution in the matrix of the capillary-porous
body of wood, and compatibility with wood material.
In turn, the impregnant distribution is determined by
various factors and process parameters. Capillary-dif-
fusion impregnation of wood remains practical for
goods with high end surface fraction, particularly, for
friction assembly bushings, compressed-wood fric-
tionless bearings, and end face parquet and wall panels
. In accomplishing a specific task of impregna-
tion, it is advisable to develop an adequate mathe-
matical model for the impregnant distribution along
the fibers of a sample, as influenced by the process
time and characteristics of the impregnant.
To describe the impregnant distribution in a wood
sample with thickness h, which is small compared
to the sample length and width, the second Fick’s law
for 1D diffusion along the x axis is used:
ÄÄ = D
is the effective mass-transfer coefficient
along the x axis; t, impregnation time; and c, im-
pregnant concentration per unit volume (or weight) of
Assume that at t = 0 the material contains no im-
pregnant and the impregnant concentration in solution
In the study, we used Eq. (1) at the following ini-
tial and boundary conditions: at t =0c(x,0)=0,
. In this case, we obtain
=(2n 3 1)p/2 are the characteristic series
roots; n is a natural number; R
, half-width of the sam-
, Fourier criterion (dimensionless
time); c(x, t), current impregnant concentration in
the wood (%); and c, equilibrium impregnant concen-
tration in the wood (%).
Let us apply Eq. (2) to estimate the effective mass
transfer coefficient. At a sufficiently long impregna-
tion time (t > 80 min), we can take only the first
term of the series, which introduces a relative error of
no more than 1%.
We denote the impregnant content in the wood
sample by c(0, t)=A
); the maximal impreg-
nant content in the sample, by c
the degree of process completeness, by F = A
Then we obtain for D
= 3 ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ .
[0.24 + ln(1 3 F )]h
In the study, we used samples of birch, pinetree, and
oak with dimensions a 0 b 0 h =400 40 0 1.5 mm,
which corresponds to the infinite board model.
The current sorption was estimated by Eq. (4).
(t) 3 m
is the weight of the initial absolutely dry
sample (g), and m(t), current weight of the impreg-
nated sample dried to constant weight (g).
In the study, we used synthetic oligomers of 4-vi-
nylcyclohexene (VCH) with styrene [SKT-70 (numeral