AND POLYMERIC MATERIALS
Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 3, pp. 437−441.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © V.A. Zhorin, M.R. Kiselev, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 3, pp. 465−469.
Thermal Processes in Methacrylamide
after High-Pressure Plastic Deformation
V. A. Zhorin and M. R. Kiselev
Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
Received February 3, 2011
Abstract—The effect of high pressure (0.5–2.0 GPa) on the methacrylamide polymerization under the conditions
of plastic deformation performed on high-pressure anvil-type devices was studied. Thermal processes in samples
subjected to deformation at different pressures and the effect of UV irradiation on the enthalpies of the monomer
polymerization in a melt and of the high-temperature endothermic process in deformed samples were examined.
Polymerization and copolymerization of various
vinyl monomers under the conditions of high-pressure
plastic deformation occur without specially added
initiators and catalysts. The mechanism of the initiation
of the chemical process under such action is not
One of the monomers best studied by now is
acrylamide. It is known that the amount of polyacrylamide
formed under deformation at constant pressure increases
with an increase in the anvil turn angle (degree of
deformation). An increase in the pressure leads to the
process acceleration, but, the higher the pressure, the
less pronounced is the effect of its further increase on
the polymerization rate .
It is known that acrylamide polymerizes thermally
in a melt at a temperature exceeding by 80°C Т
monomer, with an enthalpy of 270–280 J g
. In ,
we studied by DSC the thermal processes in acrylamide
preliminarily subjected to deformation under a pressure
of 1.0 and 2.0 GPa; in this case, the samples were
mixtures of the unchanged monomer and polyacrylamide
formed. In such samples, Т
of the monomer decreased
by 35°C, and thermal polymerization occurred in the
temperature interval of melting of the monomer with the
enthalpy almost 2.5 times higher than the enthalpy of
thermal polymerization of the starting monomer. Thus,
high-pressure plastic deformation not only initiates the
acrylamide polymerization, but also strongly affects the
thermal polymerization of the monomer remaining in
the deformed samples.
It is known that, under common conditions,
methacrylamide is less active than acrylamide. This
is attributed to the presence in the methacrylamide
structure of methyl group, which is an electron donor
and affects the polarization of the С=С bond.
It is interesting to study both the polymerization of
such monomer under high-pressure plastic deformation
and the thermally initiated processes in the pressure-
For the studies we used methacrylamide with Т
110°С. High-pressure deformation was performed
with high-pressure devices of Bridgman anvil type at
pressures of 0.5, 1.0, and 2.0 GPa at room temperature.
To determine the monomer conversions at various
pressures and anvil turn angles, the samples after the
pressure treatment were washed with ethanol to remove
the unchanged monomer and dried at 40°С to constant
weight. The DSC studies were performed with a DSC
Q 100 calorimeter (TA Instruments) under Ar in the