ISSN 1070-4272, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 7, pp. 1126 !1129. + Pleiades Publishing, Ltd., 2007.
Original Russian Text + N.I. Kurbanova, A.M. Kuliev, 2007, published in Zhurnal Prikladnoi Khimii, 2007, Vol. 80, No. 7, pp. 1156 !1159.
AND POLYMERIC MATERIALS
Composite Materials Based on Modified
N. I. Kurbanova and A. M. Kuliev
Institute of Polymeric Materials, Azerbaijan National Academy of Sciences, Sumgait, Azerbaijan
Received November 27, 2006
Abstract-Effect of fabrication procedure of rubber stocks on the strength and fatigue performance of com-
posite materials based on modified butadiene3styrene rubber was examined.
For more than a century scientists attempted to
obtain a synthetic elastomer with the structure and
physical properties close to those of natural rubber
(NR). Modern rubber industry uses essentially buta-
diene3styrene copolymer (SKS) as a source, because
of its availability and low cost.
SKS is an elastomer suitable for fabrication of
tires and other rubber goods. However, SKS exhibits
some disadvantages as compared to NR, primarily,
high hysteresis (strong heat liberation in multiple
SKS-based rubbers stocks are prepared at high
temperatures. As a result of increased elastic recovery,
the stocks exhibit a relatively high shrinkage. Further-
more, oil-filled stocks are characterized by uneven
surface. These drawbacks may be overcome through
optimization of the formulation, e.g., by combining
unfilled with oil-filled SKS, introducing phenol3
formaldehyde resins (to improve the adhesiveness)
and special plasticizers and carbon black (to improve
the workability) [2, 3].
The drawback of all types of synthetic rubber (SR),
complicating their use in tire industry, is lower
strength (cohesion strength) of raw compounds on
their bases as compared to those based on NR, which
is due to more perfect macroscopic structure of NR,
which facilitates its crystallization at low deforma-
tion, and also to the lack of low-molecular-weight
The cohesion strength of SR-based stocks can be
considerably improved through functionalization of
the macromolecules and also by blending two or
more polymers .
Conditions of fabrication and processing of rubber
stocks as well as the use of additives strongly affect
their structure and properties .
In this study we examined the effect of fabrication
procedure of rubber stocks on the mechanical char-
acteristics of composites based on modified SKS.
In the experiments we used SKS-30 ARKM-15
(up to 30% styrene, MW 320000, unsaturation
70 mol %, Mooney viscosity 45); SKI-3 (94% cis
units, MW 550000, unsaturation 96 mol %, Mooney
viscosity 61); SKS modified with trichloroacetic acid
(SKS-I) (chlorine content 0.8 wt %, carboxy group
content 0.5 wt %); and SKS modified with alkyl tri-
chloroacetate (SKS-II) (chlorine content 0.6 wt %,
carbonyl group content 0.3 wt %). SKS-I and SKS-II
were prepared in benzene in the presence of benzoyl
The rubbers were mixed under laboratory condi-
tions using 1600320 mm rollers at a friction ratio of
1 : 1.24 and a temperature not exceeding 40oC.
The stocks were vulcanized in an electrically
heated vulcanizing press at 143oC and hydraulic pres-
sure of 110+5 atm, using 1-mm-thick molds. The ten-
sile tests were carried out on a tensile-testing machine
at a strain rate of 200 mm min
We tested the following vulcanizates of polymer
blends: (1) standard stocks consisting of 100% SKS
(mod. SKS) or SKI-3 with 50 wt parts of S301 carbon
black (vulcanizing system: sulfur + zinc oxide +
Altax + diphenylguanidine); (2) standard stocks based
on SKS (mod. SKS)/SKI-3 (50 : 50 wt/wt), filled with
N242 high-structure carbon black (55 wt %) (vul-
canizing system: sulfur + Oktofor-10 alkylphenol3sul-
fide3formaldehyde oligomer + zinc oxide + N-oxadi-