Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 11, pp. 1993−1996.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © Zh.G. Grigoruk, Yu.N. Orlov, S.V. Levanova, N.V. Abramova, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 11,
AND POLYMERIC MATERIALS
Oxidative Bromination of Isoprenyl Units
of Butyl Rubber with the Hydrobromic
Zh. G. Grigoruk
, Yu. N. Orlov
, S. V. Levanova
, and N. V. Abramova
Tol’yattikauchuk Limited Liability Company, Togliatti, Samara oblast, Russia
Samara State Technical University, Samara, Russia
Received January 21, 2011
Abstract—Synthesis of bromo butyl rubber using the hydrobromic acid–sodium hypochlorite system as brominating
agent was studied.
An important line in creating new polymeric materi-
als is chemical modiﬁ cation of already known products
instead of the development of new large-tonnage pro-
duction processes. This approach allows considerable
saving of material and energy resources. For example,
the polymer halogenation procedure, which is being
actively developed, opens prospects for the replacement
of traditional products by materials surpassing them in
service characteristics .
The only method used in industry for the production of
halogenated butyl rubbers is halogenation of butyl rubber
(BR) with molecular halogens [2, 3]. Serious drawbacks
of the process are environmental hazard and the loss of
halogen in the form of hydrohalic acids.
Active search for effective and economically accept-
able oxidants is being performed today.
Previously we reported on procedures for preparing
halobutyl rubbers by halogenation of BR with tert-butyl
hypochlorite (TBHC)  and with systems sodium
bromide–TBHC [5, 6] and sodium bromide–sodium
hypochlorite–phosphoric acid .
It was shown that, with TBHC used as oxidant for
preparing bromo butyl rubber (BBR), the reaction occurs
via intermediate steps of formation of hypobromous acid
and bromine. The reaction of bromine with isoprenyl
units of butyl rubber yields substitution products of
mainly exomethylene structure, which ensures high
rate of rubber vulcanization with systems based on zinc
oxide. Furthermore, the bromination is not accompanied
by the rubber degradation, which allows less stringent
requirements to be imposed on the starting polymer with
respect to unsaturation and Mooney viscosity. However,
because TBHC is expensive and dangerously explosive,
it was suggested to replace it by sodium hypochlorite,
which is a relatively safe, available, and cheap reagent.
The use of the sodium bromide–sodium hypochlorite–
phosphoric acid system for butyl rubber bromination
also results in the formation of structures of allyl halide
type and is not accompanied by rubber degradation, but
because of increased number of reactants the process
control in industry becomes considerably complicated.
It was interesting to examine the possibility of using
for BBR synthesis a simpler redox system, sodium
The BR bromination was performed in the temperature
interval 276–298 K. Hydrobromic acid was introduced
into a solution of butyl rubber in isopentane with stirring