ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 8, pp. 1381!1383. + Pleiades Publishing, Inc., 2006.
Original Russian Text + Ch.Sh. Ibragimov, F.A. Novruzova, Kh.Sh. Gadzhiakhmedzade, F.R. Khalafov, 2006, published in Zhurnal Prikladnoi Khimii,
2006, Vol. 79, No. 8, pp. 1394!1396.
Kinetics of the Reaction of Polyisobutylene Modification
with Acrylonitrile and Vinyl Acetate
Ch. Sh. Ibragimov, F. A. Novruzova, Kh. Sh. Gadzhiakhmedzade, and F. R. Khalafov
Institute of Chemical Problems, National Academy of Sciences of the Republic of Azerbaijan, Baku, Azerbaijan
Received December 1, 2005; in final form, March 2006
Abstract-Kinetic parameters of the reaction of polyisobutylene modification with acrylonitrile and vinyl
acetate were calculated. The reaction rate constants were obtained for three temperatures, and the activation
energies and the preexponential factor were determined for modification of polyisobutylene with acrylonitrile
and vinyl acetate. The effect of the AlCl
concentration on the kinetic parameters of the reaction of polyiso-
butylene modification was studied.
The development of methods for modification of
polyisobutylene (PIB) with polar monomers in the
presence of Lewis acids opens up wide opportunities
for control over its properties, which extends the syn-
thetic capacity of polymer chemistry.
Polymers of isobutylene are large-tonnage products
that find wide use in various areas of industry and
technology. Polyisobutylene belongs to the class of
saturated polyolefins, which determines their compar-
atively high stability against corrosive media (acids,
It is a common knowledge that Lewis acids (Frie-
del3Krafts catalysts) are used in organic chemistry
and carbocation polymerization of olefins and dienes
as catalysts of electrophilic reactions. It has been
found, however, that, under mild conditions (203
60oC), strong Lewis acids (AlCl
activation of polyisobutylene and butyl caoutchouc by
the free-radical mechanism . EPR spectroscopy
and quantum-chemical calculations confirmed that
paramagnetic centers are formed in catalytic destruc-
tion of PIB [2, 3].
As evidence in favor of the radical-chain mechan-
ism of destruction served results of calorimetric and
C NMR studies of samples of destructed PIB [5, 6],
which demonstrated that polyolefins (?PIB) with
branched structure are formed. The data obtained
were used to develop a method for synthesis of iso-
butylene copolymers with polar monomers, acrylo-
nitrile (AN) and vinyl acetate (VA) . Therefore,
construction of a kinetic model of PIB modification
with AN and VA on the basis of the data obtained
and calculation of the kinetic parameters of these
processes seem to be necessary for solving the prob-
lem of development of a polymeric material on their
The paper reports the results of kinetic studies of
the reaction of PIB modification with polar monomers
AN and VA in n-hexane in the presence of the acid
(Tables 1, 2).
The reaction rate is described by the equation
which gives, with account of the initial conditions,
the following equation for the rate constant of the re-
action of PIB modification with acrylonitrile:
k = 7 7777777 ln 7777777777 .
are the initial concentra-
tions of AN and PIB in the reaction mixture (g g
, concentrations of AN and PIB in
the copolymer (g g
); and t, time (h).
Equations similar to (1) and (2) were also derived
for the reaction of PIB modification with vinyl ace-
tate. In this case, [VA]
are substituted for
in Eqs. (1), (2).