Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 10, pp. 1880−1882.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
Zh.G. Grigoruk, Yu.N. Orlov, S.V. Levanova, N.V. Abramova, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 10,
Oxidative Bromination of Isoprenyl Links
of Butyl Rubber by the System Sodium Bromide–Sodium
Zh. G. Grigoruk, Yu. N. Orlov, S. V. Levanova, and N. V. Abramova
“Tol’yattikauchuk” (Limited Liability Company), Samara State Technical University, Samara, Russia
Received January 20, 2010
Abstract—Results of studying kinetics of the bromination of isoprenyl links of butyl rubber by the system
sodium bromide-sodium hypochlorite-phosphoric acid are presented. Reaction orders with respect to the reagents
were determined, and the value of the observable activation energy was estimated.
It is known that the halogenation of oleﬁ ns and their
derivatives in a liquid phase can pass by two competing
directions with the formation of substitution and addition
products. A considerable yield of substitution products
was observed for compounds containing a quaternary
carbon atom at a double bond [1, 2]. Thus, the reaction of
a halogen (chlorine or bromine) with a butyl rubber (BR)
isoprenyl link under certain conditions passes practically
quantitatively in the direction of the substitution to form
allylhalide structures .
The optimization of the existing technology of the
production of halogen-containing butyl rubbers is directed
at the reduction of the number of technological stages,
at rising the proﬁ tability and ecological compatibility of
processes, and also at the study of alternative halogenat-
ing systems [4, 5].
Earlier we reported the study of the direct and oxida-
tive BR halogenating using systems based on tret-butyl-
hypochlorite (TBHC) [6, 7], which is an unstable product,
therefore its transportation involves difﬁ culties connected
with a possibility of its decomposition under the action of
heat or radiation. Sodium hypochlorite is a coproduct of
chloroorganic production and, unlike TBHC, it is a low-
hazard and more accessible and low-cost oxidizing agent.
This work is devoted to the study of kinetic regularities of
the reaction of oxidative BR bromination by the system
sodium bromide-sodium hypochlorite-phosphoric acid.
Oxidative bromination of BR was carried out in the
temperature range of 278–298 K. Beforehand BR was dis-
solved in isopentane at a room temperature. The input of
reagents in the BR solution was realized in the sequence:
a 20% sodium bromide solution, a sodium hypochlorite
solution containing 150–200 g l
of active chlorine, and
a 10% solution of phosphoric acid.
Periodically samples were taken from the reaction
mass, rubber was isolated and analyzed for the bromine
content by burning the sample with the following mer-
curymetric titration .
The rate of the bromination reaction was estimated by
a mathematical treatment of time dependences of bromine
accumulation in rubber at various concentrations of initial
reagents. The initial reaction rate was calculated as the
ﬁ rst derivative of the fourth-power polynomial:
y = a + bx + cx
The target product structure was determined by the
Н NMR spectroscopy at a room temperature using an
Avance III Bruker NMR spectrometer with a working
frequency of 400 MHz.
The total equation of the reaction of brominating iso-
prenyl BR links by the system sodium bromide-sodium
hypochlorite-phosphoric acid can be presented as follows: