Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 1, pp. 128−132.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © O.V. Lebedeva, Yu.N. Pozhidaev, N.S. Shaglaeva, S.S. Bochkareva, L.A. Es’kova, 2011, published in Zhurnal Prikladnoi Khimii, 2011,
Vol. 84, No. 1, pp. 128−132.
AND POLYMERIC MATERIALS
O. V. Lebedeva, Yu. N. Pozhidaev, N. S. Shaglaeva,
S. S. Bochkareva, and L. A. Es’kova
Irkutsk State Technical University, Irkutsk, Russia
Received April 16, 2010
Abstract—Copolymers of N-vinylpyrazole with N-vinyl-4,5,6,7-tetrahydroindole and vinyl acetate were prepared
by radical copolymerization. The composition, structure, and properties of the copolymers were studied. The
reactivity constants of the monomers were calculated. Copolymer ﬁ lms were prepared from solutions by casting,
and the proton conductivity of the ﬁ lms was determined.
Vinyl derivatives of nitrogen-containing heterocyclic
compounds are of particular importance. Macromolecular
compounds based on them have diverse structures,
which opens wide prospects for the development of
materials with good mechanical, optical, electrical,
and thermal properties. High polymerization activity
of nitrogen-containing monomers in copolymerization
allows the composition and hence the properties of the
resulting polymers to be readily varied.
The radical copolymerization of N-vinyl-3(5)-
methylpyrazole (VMP) with vinyl acetate (VA), meth-
acrylic acid, and styrene was studied previously [1–3].
These studies showed that in such systems VMP is the
most reactive comonomer. Introduction of VMP units
into polyvinyl acetate macromolecules increases the
heat resistance of the polymers to 290°С . Data on
copolymers of N-vinylpyrazole (VPyr) with VA and
N-vinyl-4,5,6,7-tetrahydroindole (VTHI) are lacking. In
this study we prepared such copolymers and examined
their structure and reactivity.
N-Vinylpyrazole was prepared by the procedure
described in  in accordance with the reaction
VTHI was prepared in 93% yield by Troﬁ mov reaction
Commercially available vinyl acetate was puriﬁ ed
by vacuum distillation.
Radical copolymerization in the systems VPyr–
VTHI and VPyr–VA was performed at 60°С in ampules
in benzene and DMF solutions. Azobis(isobutyronitrile)
was used as initiator. After the copolymerization
completion, the cooled ampules were opened. The
VPyr–VTHI reaction mixture was dissolved in benzene,
and the product was precipitated with hexane. The
VPyr–VA reaction mixture was dissolved in DMF, and
the product was precipitated with ice-cold water. The
copolymers were reprecipitated twice and vacuum-dried
to constant weight.
Turbidimetric titration was performed with a KFK-2
photometer at λ = 670 nm. Titration experiments were
performed with solutions of VPyr–VTHI copolymer