ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 5, pp. 800−807. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © A.E. Zaikin, G.B. Bobrov, 2015, published in Zhurnal Prikladnoi Khimii, 2015, Vol. 88, No. 5, pp. 757−765.
AND POLYMERIC MATERIALS
Compatibilization of Polypropylene and Butadiene–Acrylonitrile
Rubber Using an Organic Peroxide
and an Oligoether Acrylate
A. E. Zaikin and G. B. Bobrov
Kazan National Research University of Technology, ul. Karla Marksa 72, Kazan, Tatarstan, 420111 Russia
Received April 10, 2015
Abstract—The relationships and causes of changes in the deformation and strength properties of a blend of
polypropylene with butadiene–acrylonitrile rubber with variation of the content of an organic peroxide, 2,5-di-
methyl-2,5-di(tert-butylperoxy)hexane, and an oligoether acrylate, triethylene glycol dimethacrylate, were studied.
The observed changes in the deformation and strength properties of the blend were accounted for on the basis of
the experimental data on the density of the vulcanization network of the butadiene–acrylonitrile rubber, on the
morphological structure of the blend, on the adhesion between the polymers, and on the degree of crystallinity
and molecular mass of polypropylene.
The growing demand for oil-resistant materials
requires making processes for their production simpler
and cheaper. One of such processes is production of
oil-resistant thermoplastic elastomer (TPE) by reactive
mixing of polymers that exhibit high resistance to hot oil.
Polypropylene (PP) and butadiene–actylonitrile rubber
(NBR) are resistant to the action of oil and are relatively
readily available. Therefore, they are suitable components
for developing oil-resistant thermoplastic elastomer by
the above procedure.
Although papers aimed at developing TPEs based
on PP–NBR blends are numerous and diverse [1–18], a
procedure allowing production of a material exhibiting
minimal oil absorption, high physicomechanical and
deformation characteristics, and good processability
by a relatively simple and cheap process has not yet
been developed. The main problem is extremely low
compatibility between nonpolar polypropylene and polar
butadiene–acrylonitrile rubber . In some studies
[1–3, 5], this problem is solved by preparing special
block copolymers that contain groups exhibiting afﬁ nity
for both polymeric components and by introducing these
copolymers into the PP–NBR blend. Such procedure,
though giving good result, is very sophisticated and
expensive in implementation.
The possibility of preparing graft copolymers of
PP and NBR directly in the course of their mixing in
the viscous-ﬂ ow state (in situ) seems to be the most
attractive. Such synthesis can be attempted, e.g., in the
presence of an initiator of radical chain processes and
of polyfunctional oligomers (PFOs) capable of graft
copolymerization with both polymeric components .
Grafting of trimethylolpropane triacrylate (TMPTA) [21,
22], triallyl isocyanurate (TAIC) , pentaerythritol
tetraacrylate (PETeA) , and pentaerythritol
triacrylate (PETA) [21, 24] to polypropylene in the
presence of various organic peroxides has been reported.
In addition, owing to structural features, all these PFOs
are well compatible with NBR and are used as coagents
in peroxide vulcanization [25, 26]. Taking into account
the possibility of the reactions of the above compounds
with both polymeric components, we can anticipate the
formation of the PP–PFO–NBR graft copolymer in the
course of joint mixing of PP, NBR, PFO, and organic
peroxide, which should enhance the compatibility of
PP and NBR.