1070-4272/05/7804-0617 + 2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 4, 2005, pp. 617!622. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 4, 2005,
Original Russian Text Copyright + 2005 by Khimich, Rakhmatullina, Slabospitskaya, Tennikova .
AND POLYMERIC MATERIALS
Synthesis and Pore Structure of Monolithic Polymeric Sorbents
G. N. Khimich, E. N. Rakhmatullina, M. Yu. Slabospitskaya, and T. B. Tennikova
Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg, Russia
Received June 1, 2004; in final form, February 2005
Abstract-The pore structure of monolithic sorbents prepared by photoinduced copolymerization of 2,3-ep-
oxypropyl methacrylate with ethylene glycol dimethacrylate was studied. The parameters of the pore structure
of these copolymers were examined as influenced by the quantitative ratio of pore-forming agents and the type
and concentration of the initiators.
Macroporous monolithic materials are homoge-
neous solid organic or inorganic matrices containing
pores of various sizes. These materials are formed by
copolymerization of appropriate monomers in the pres-
ence of pore-forming agents . Their pore structure
is stable, i.e., its parameters do not change when the
solid sorbent is immersed in a solvent. Monolithic
copolymers of 2,3-epoxypropyl methacrylate (glycidyl
methacrylate, GMA) and ethylene glycol dimethacry-
late (EDMA) were prepared for the first time and sug-
gested as sorbents for high performance liquid chro-
matography in the late 1980s-early 1990s . At
present, these stationary phases characterized by fast
interphase mass transfer are widely used for biosep-
aration (including affine chromatography) and bio-
conversion (enzymatic reactors) [1, 7314].
The polymers have a high chemical resistance, op-
timal morphology providing accessibility of the po-
rous surface to adsorbents, and unique hydrodynamic
properties, which make them promising for use in
interphase dynamic processes. These sorbents can
be prepared as articles of various shapes (discs, pipes,
rods) by polymerization in appropriate molds. The av-
erage pore size of macroporous GMA3EDMA poly-
mer is 1 mm, and it can be readily controlled by
the copolymerization conditions. This copolymer has
a well-balanced ratio of hydrophobic and hydrophilic
groups and a high concentration of reactive epoxy
groups allowing ready grafting of affine ligands (pro-
teins) and their fragments (peptides) to the pore sur-
face to form effective materials for protein analysis.
Usually, macroporous monolithic polymers are
prepared by in situ radical thermal polymerization
in a closed mold of a required size and shape. Photo-
induced polymerization, unlike thermal polymeriza-
tion, can be performed at room temperature in a low-
boiling solvent acting as a pore-forming agent .
Photoinduced free-radical polymerization is widely
used in production of microchips . This method
is also used to prepare monolithic materials .
However, the influence of the reaction conditions on
the polymer properties is not understood.
Here we studied how the pore structure of thin
films of GMA3EDMA copolymers is formed under
conditions of photoinduced copolymerization. We op-
timized the polymerization conditions with the aim to
prepare macroporous materials whose homogeneous
morphology can be controlled in the course of their
We used GMA (Fluka Chemie AG, Switzerland),
EDMA (Sigma-Aldrich GmbH, Germany), cyclohex-
anol (CHL) (Sigma-Aldrich GmbH, Germany), 1-do-
decanol (DDL) (Reakhim, Russia), 2,2-dimethyl-2-
hydroxyacetophenone (Darocure-1173) (Merck-Schu-
chard, Germany), benzophenone (BP) (Reakhim,
Russia), 2,2-azodiisobutyronitrile (AIBN) (Merck-
Schuchard, Germany), and methylene blue dye
(MBD) (Sigma-Aldrich GmbH, Germany).
In all the model experiments, we used a mixture of
GMA (0.24 ml), EDMA (0,16 ml) (6 : 4 volume ra-
tio), mixture of pore-forming solvents CHL and DDL
(0.6 ml) (the ratio of these solvents was varied), and
AIBN, BP or Darocure-1173 initiator. Prior to the re-
action onset, nitrogen was bubbled through the mix-
ture to remove oxygen inhibiting the polymerization.
The photoinduced copolymerization was performed
at room temperature (20oC) in special plastic con-