AND POLYMERIC MATERIALS
Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 5, pp. 739−746.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © G.P. Grabchuk, N.A. Derevyanko, A.A. Ishchenko, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 5, pp. 792−799.
Effect of Electron-Donating Ability of Terminal Groups
of Cationic Polymethine Dyes on Thermal Polymerization
of Methyl Methacrylate in Solution
G. P. Grabchuk
, N. A. Derevyanko
, and A. A. Ishchenko
Institute of High Technologies, Kyiv National Taras Shevchenko University, Kyiv, Ukraine
Insitute of Organic Chemistry, Ukrainian Academy of Sciences, Kyiv, Ukraine
Received July 12, 2012
Abstract—Thermal polymerizability of methyl methacrylate solution was examined in dimethylformamide in
the presence of cationic symmetric and asymmetric polymethine dyes with different terminal electron-donating
groups by dilatometric method. It was found that the polymethine dyes according to the electronic structure can
initiate or inhibit the polymerization of methyl methacrylate both in the presence of standard initiator, azoisobu-
tyronitrile, and in its absence by a radical mechanism. It was shown that the initiating ability was weakened with
altering an electron-donating activating ability of terminal groups of dyes from the average level in both directions
of its increasing or decreasing. The transition from symmetric to asymmetric dyes in the same structural type is
accompanied by a loss of initiating ability. Based on the comparison of experimental kinetic data of polymeriza-
tion of methyl methacrylate in the presence of dyes and quantum chemical calculations of electronic structure for
dyes it was demonstrated that a HOMO energy value of an initiating dye must be higher and that of an inhibiting
dye, lower than the methyl methacrylate value.
Creating colored polymers with desired properties is
one of the most topic challenges of modern chemistry, as
these polymers are widely used in laser  and scintillation
technique , devices for recording information , solar
power [2, 4, 5], optoelectronics [6–8], electroluminescence
[4, 8, 9]. These polymer materials possess a number of
operating advantages over the colored liquid materials
as a result of a more simple and convenient design, non-
toxicity, ability to operate in a wide temperature range
(from minus to plus temperatures) and zero gravity [1–6].
Polymethylmethacrylate (PMMA) has significant
advantages over other polymer matrices due to its
excellent optical and mechanical properties, high weather
resistance, small water absorption, and low cost .
The best physicochemical and colored PMMA optical
characteristics are achieved by polymerizing methyl
methacrylate (MMA) with dyes dissolved in it .
Until now, polymerization of MMA was carried out in
the presence of anthraquinone, xanthene, indigo dyes
. Polymethine (cyanine) dyes (PD) despite the largest
variety of photochemical and photophysical properties
among organic dyes [8, 10, 11], were studied only in
several papers for this purpose [12, 13]. It was found
that the PD depending on the length of the polymethine
chain are able to accelerate or slow down the radical
The aim of the study was to examine kinetics of
thermal polymerization of MMA in solution in the
presence of cationic PDs with different terminal electron-
Symmetrical 1–5 and asymmetric 6–8 dyes  with
varying level of electron-donating activity of terminal
groups at the same length of the polymethine chain were
choiced as an object of the study.
Note that no researched dyes have functional groups,