1070-4272/05/7808-1355 C 2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 8, 2005, pp. 1355!1359. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 8, 2005,
Original Russian Text Copyright + 2005 by Kurbanova.
AND POLYMERIC MATERIALS
Influence of Modification on the Elastic-Relaxation Properties
of Rubbers Based on Binary Blends of Diene Rubbers
N. I. Kurbanova
Institute of Polymeric Materials, Azerbaijan National Academy of Sciences, Sumgaiyt, Azerbaijan
Received April 21, 2005
Abstract-The elastic-relaxation properties of rubbers based on binary blends of diene rubbers were studied
as influenced by the modifier, trichloroacetic acid.
The current trends in the development of chemistry
and technology of composite materials are largely
determined by the search for ways to develop mate-
rials with an improved set of properties. An effi-
cient way to prepare new materials with desired prop-
erties consists in mixing of two or more polymers
. The conditions of preparation and processing
of blends and introduction of various modifying ad-
ditives strongly affect their structure and properties
. Polymer blends offer a number of advantages
over conventional polymeric materials and often stim-
ulate rapid scientific and technological progress in
their application fields.
We have demonstrated earlier  how fillers affect
the elastic-relaxation and strength properties of rub-
bers based on binary blends of diene rubbers . In
this study, we elucidated how the modifier affects
the properties of binary blends of divinyl (SKD) and
butadiene-styrene (SKS) rubbers with polyisoprene
We used Cariflex IR309 polyisoprene available
from Shell, cis-132 (96% cis) SKD, SBR-1500 SKS
(styrene 23%) available from BSL Olefinverbund
GmbH, Schkopau, and carbon black no. 330. Tri-
chloroacetic acid (TCAA) (mp 58oC, bp 196.5oC)
served as modifier.
The component ratio, mass fractions, in the for-
mulations was as follows: SKD (SKS) : SKI : carbon
black : TCAA = 50 : 50 : 50 : 5. Vulcanizing system,
mass fractions: sulfur 2.0, stearic acid 2.0, ZnO 3.0,
thiuram 0.65, Altax 1.0, Captax 1.25 for SKD/SKI
blend, and sulfur 2.0, stearic acid 2.0, ZnO 2.0, and
Altax 2.75 for SKS/SKI blend.
The rubbers were mixed under laboratory condi-
tions in a 60-cm
Brabender Plasticorder mixer (initial
temperature 50oC, degree of filling 0.75) for 6 min
in the case of systems without the filler and for 7, 10,
and 15 min in the case of formulations with the filler.
The time, s, of introduction of the components into
the mixer was as follows: SKD (SKS) 0, TCAA 60,
SKI 120, carbon black 180 (in three portions), sul-
fur + stearic acid + ZnO + accelerators 240.
The blends were pressed in 1-mm-thick molds at
The tensile tests were carried out on a tensile-test-
ing machine at room temperature and a strain rate of
200 mm min
A dynamic mechanical analysis was carried out
on a Gabo Qualimeter Eplexor 500 N (T from
3120 to 120oC, frequency 1 Hz) at a heating rate of
1 deg min
We studied the physicomechanical properties of
the initial filled and unfilled, as well as modified,
vulcanizates of the resulting formulations under quasi-
static and dynamic loads. The compositions and prop-
erties of the binary blend formulations (average of
five measurements) are listed in the table.
As is known , of greatest interest in the case
of elastomeric formulations is introduction of minor
additives of highly polar compounds. They spread over
the surface of the structural elements of the macro-
molecules, increase their mobility, and accelerate re-
laxation processes, thereby improving the properties
of the polymeric materials.
With a modifier containing chlorine atoms and
a carboxy group, it is possible to introduce into the
elastomers functional groups creating new reactive
centers that enhance their interaction with isoprene
rubber and other components of the rubber stock.