ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 4, pp. 714 !716. + Pleiades Publishing, Ltd., 2008.
Original Russian Text + N.A. Kopylova, Yu.D. Semchikov, S.D. Zaitsev, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 4,
pp. 678 ! 680.
Thermal Oxidative Degradation of Polymethacrylates
Synthesized by Pseudoliving Radical Polymerization
N. A. Kopylova, Yu. D. Semchikov, and S. D. Zaitsev
Lobachevsky Nizhni Novgorod State University, Nizhni Novgorod, Russia
Received December 14, 2007
Abstract-The kinetics of degradation of polymethyl methacrylate, polybutyl methacrylate, and
poly-2,2,3,3-tetrafluoropropyl methacrylate synthesized by pseudoliving radical polymerization at 270oC
in air in the presence of bis(triphenylphosphine)(3,6-di-tert-butyl-1,2-semiquinolato)copper(I) was studied.
The possibility of improving the thermal treatment of the resulting polymers was revealed.
Pseudoliving radical polymerization allows syn-
thesis of polymers and copolymers with controlled
molecular weight and narrow molecular-weight distri-
bution, which largely affects their physicomechanical
characteristics. There are several methods for imple-
mentation of this process: radical polymerization with
reversible inhibition by stable free radicals (SFRP),
radical polymerization with halogen atom transfer
(ATRP), and polymerization by degenerate chain
transfer by reversible addition-fragmentation (RAFT)
. In all these cases, the chain termination is con-
trolled by the reversible reaction of the chain-termi-
nating agent with the propagating radical. Macromo-
lecules of polymers contain terminal groups bound to
the chain by a labile bond that can be activated under
thermal or photochemical action.
In this study, we used a copper semiquinolate com-
semiquinolato)copper(I) (CSQ) for synthesis of poly-
methacrylates by the SFRP method. The structure of
this complex is presented below:
The process was performed at 25oC under UV ir-
radiation. Methyl methacrylate (MMA), butyl meth-
acrylate (BMA), and 2,2,3,3-tetrafluoropropyl meth-
acrylate (FMA) were used as monomers. Under the
above conditions, the polymerization exhibited all
features of a pseudoliving radical process: linear de-
pendences of the average molecular weight on the de-
gree of conversion, lower values of the polydispersity
, and initiation of secondary poly-
merization of monomers with polymers synthesized
in the presence of CSQ [4, 5].
The kinetic curves of degradation of reprecipitated
samples of polymers are shown in Figs. 1 and 2.
Fig. 1. Kinetic curves of degradation of polyMMA in
air at 270oC. (Dp/p
) Decomposition of volatile products,
and (t) time; the same for Fig. 2. (1) [CSQ] = 0, (2) CSQ
is introduced into the prepared polymer via the solution,
(3) polymer is synthesized by secondary polymerization of
MMA initiated with polyMMA (5 wt %) from run no. 4,
and (4) [CSQ] = 4 0 10