1070-4272/05/7804-0633 C 2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 4, 2005, pp. 633!635. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 4, 2005,
Original Russian Text Copyright + 2005 by Imankulova, Kondrashev, Val’tsifer.
AND POLYMERIC MATERIALS
Curing of Epoxy-containing Oligomers with Oxidized
S. A. Imankulova, N. B. Kondrashev, and V. A. Val’tsifer
Institute of Technical Chemistry, Ural Division, Russian Academy of Sciences, Perm, Russia
Received October 5, 2004; in final form, February 2005
Abstract-The physical properties of polymeric composites based on polydieneurethane-diepoxide and filled
with particles of carbon black of various degrees of oxidation were studied.
Modern composite materials are not only multi-
phase in the polymeric composition but also contain
mineral fillers, which determines nonuniformity of
the polymer3inorganic phase boundary. Thus, filled
composites can be regarded as a micrononuniform
and microheterophase system.
The activity of a filler depends on its specific sur-
face area, morphology, and chemical and energy char-
acteristics of the surface; the interphase interaction
with the polymer is determined by the specific surface
Since carbon black (CB) is widely used as highly
active filler of polymeric materials , it seemed
advisable to study the mechanical properties of the po-
lymer as influenced by the acidity and content of
oxygen-containing groups on the CB surface. Cer-
tain parts of the CB particle surface can be occupied
by various functional groups appearing in the course
of oxidation of the filler surface by atmospheric ox-
ygen; just these parts can form strong chemical bonds
with polymers. The chemical principles of formation
of highly filled materials are poorly understood yet.
The goal of this study was to prepare epoxy-con-
taining polymeric composites cured with surface func-
tional groups of the filler (e.g., carbon black). This
is a particular case of such a fundamental problem
as study of processes in complex dispersion systems
with a high content of the solid phase.
The CB samples with similar particle-size distribu-
tions, but different degrees of the surface oxidation
were prepared from low-active furnace carbon black
(P-803 brand) prepared by thermal oxidative decom-
position of liquid hydrocarbon raw materials. The CB
samples were supplied by the Temp Scientific and
Technical Center (Yaroslavl, Russia).
By varying the time of thermal oxidation of the ini-
tial CB by atmospheric oxygen at 500oC, we prepared
samples with varied oxygen content (CB-1)3(CB-6).
The procedure for determining the content of ox-
ygen-containing groups on the CB surface was based
on the difference in their chemical activity. The total
content of surface oxygen-containing acidic groups was
determined by potentiometric titration with a strong
(hydrochloric) acid of a CB suspension with an aque-
ous NaOH solution, and the content of carboxy groups,
by titration of the CB suspension with an aqueous
solution, using an EV-74 pH-meter.
The mechanical tests were carried out with oligo-
diene-urethane3diepoxide (M 5000), which was mixed
with a CB filler (30 wt %) and stirred for 30 min at
50oC under reduced pressure. The composition was
cured for 10 days at 80oC, with no additional curing
The mechanical properties (elongation at break
and strength) of the filled CB composites based on
polydiene-urethane3diepoxide were determined on
an R-5 2099 tensile-testing machine at various tem-
peratures, with the measurement error of 5% accord-
ing to GOST (State Standard) 270375.
The degree of oxidation of the CB particle surface
stongly affects the surface (sorption) properties and
the structuring power of the CB . The strength of
the CB particles depends both on the micromosaic
structure of the oxidized particle surface and on the