1070-4272/05/7806-0985 C 2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 6, 2005, pp. 985!988. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005,
Original Russian Text Copyright + 2005 by Grebennikov, Smotrina, Anan’eva, Kuznetsov.
AND POLYMERIC MATERIALS
Porous Structure of Composites
S. F. Grebennikov, T. V. Smotrina, T. A. Anan’eva, and A. Yu. Kuznetsov
St. Petersburg State University of Technology and Design, St. Petersburg, Russia
Mari State Technical University, Yoshkar-Ola, Mari-El, Russia
Received January 12, 2005
Abstract-NMR and the sorption method were used to study the structure of composites based on ultra-
high-molecular-weight polyethylene and peat (filler).
Composite materials (CM) are widely used in
various fields of technology (building and construc-
tion materials, supported catalysts, porous polymeric
materials, sorption-active composites, etc.). The po-
rous structure of composites plays a primary role in
their application and determines their physicomech-
anical characteristics. In both cases, an important role
is played by the interaction of components of the com-
posite and the extent to which their surfaces overlap.
In , the notions [host] and [guest] were introduced
to characterize the interaction between the components
of composites. The scheme of the host3guest interac-
tion, suggested for catalysts , is to be extended for
polymeric formulations, especially for those cases
in which the guest is a fibrous ionexchange sorption-
active or a fibrous material that is responsible for
the large internal surface area of a composite and,
simultaneously, is its physicomechanical skeleton.
The possible schemes of the host3guest interaction
are shown in Fig. 1. In position a, the guest is totally
blocked by the polymeric matrix; in position b, part
of the guest is in position a, and the other part may
be in contact with the third phase or another part of
the host. In position c, one side of the guest adheres t
o the host surface. Scheme d is a superposition of
states a and b. Most of polymers swell in some media.
If a medium is inert for the host, but causes swelling
of the guest, the polymeric matrix may be ruptured
to give cracks (pores) (position e).
The structure of composites is analyzed by adsorp-
tion methods, and the state of the surface and the sor-
bate, by spectral techniques . Here, the polymer-
ic formulations also have specific features, because
a noninert sorbate is absorbed by the bulk of the poly-
mer and causes a sorption deformation of the polymer
[2, 3], rather than remaining at the phase boundary. In
the present study, composites based on a porous ultra-
high-molecular-weight polyethylene (UHMWP, molec-
ular weight 1.5 0 10
), which is the host, and a fil-
ler, guest, which is peat, were examined. Peat was in-
troduced into the composite in amounts of 10 (CM-1
sample) and 30 wt % (CM-2 sample). A water vapor
served as sorbate. The methods used to measure the
amount of sorption and
H NMR spectra and to form
the composites have been described previously [4, 5].
The most important characteristic of porous bodies is
their specific surface area, which is commonly found
 from the sorption capacity of a monolayer, a
), in the equation
ÄÄÄÄÄÄ = ÄÄÄ + ÄÄÄÄ h.
a(1 3 h)
1 C 3 1
Here a is the amount of sorption (mol g
); h =
, where p is the equilibrium pressure, and p
the saturated vapor pressure of the sorbate; and C is
an energy constant.
Fig. 1. Schemes of the host3guest interaction.