1070-4272/02/7503-0470$27.00C2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 3, 2002, pp. 470!473. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 3,
2002, pp. 481!484.
Original Russian Text Copyright + 2002 by Mognonov, Mazurevskaya, Volodarskii.
AND POLYMERIC MATERIALS
Polyamidobenzimidazoles as Polymeric Materials
for Cold Climate
D. M. Mognonov, Zh. P. Mazurevskaya, and L. B. Volodarskii
Baikal Institute for Nature Management, Siberian Division, Russian Academy of Sciences, Ulan-Ude,
Institute of Organic Chemistry, Siberian Division, Russian Academy of Sciences, Novosibirsk, Russia
Received July 24, 2001
Abstract-A frost-resistant polyamidobenzimidazole-based polymer composite is synthesized from 3,3`,4,4`-
tetraaminodiphenyl oxide, diphenyl adipate or diphenyl sebacate, and hexamethylenediamine or e-caprolactam.
As stabilizers for the polymers were used 4-phenyl-2,2,5,5-tetramethyl-3-imidazoline-3-oxide-1-oxyl and
It is known that, under conditions of distinctly con-
tinental climate with negative annual average tempera-
ture, polymeric materials and composites degrade
considerably more rapidly than in temperate climatic
zones . Through simultaneous effects of solar radia-
tion, moisture, and atmospheric oxygen and ozone,
polymers are subject of photooxidative and hydrolytic
degradation, resulting in significant decrease in their
molecular weight, brittle failure, and rapid deteriora-
tion of performance characteristics.
It is obvious that the frost resistance of polymeric
materials can be enhanced by modification of the
polymer composition and structure . Of particular
interest in this context are resonance-stabilized rigid-
chain heterocyclic polymers containing aromatic and
heterocyclic fragments in their macrochains.
It was demonstrated in [2, 3] that polybenzimida-
zoles (PBIs) based on aromatic tetramines and di-
phenyl esters of aromatic or aliphatic dicarboxylic
acids can be used as starting materials for preparation
of glues and binders for glass fiber reinforced plastics
which are capable to maintain high performance at
cryogenic temperatures, despite high rigidity of their
chain and high glass transition temperature. However,
in most cases PBIs are infusible compounds poorly
soluble in organic solvents, making it more difficult
to process them into goods by modern industrial
Polyamidobenzimidazoles (PABIs) reported in
[43 6] are copolymers of PBI and a polyamide whose
molecule contains benzimidazole rings and amide
bonds. They were synthesized by solid-phase poly-
condensation from 3,3`,4,4`-tetraaminodiphenyl oxide,
diphenyl adipate or diphenyl sebacate, and hexa-
methylenediamine or e-caprolactam.
Chemical modification of BPIs through introduc-
tion of aliphatic fragments in the macrochain increases
the chain flexibility and free space of the macromole-
cule, which has a favorable effect on such properties
as the solubility and plasticity. Commercial poly-
amides, which are low-resistant to the action of
climatic factors , can be stabilized by introduction
of benzimidazole rings .
It was demonstrated in preliminary tests of PABI-
that this class of copolymers show pro-
mise for exploitation under conditions of cold climate
and strong UV radiation . Good results obtained
with the films in environmental tests stimulated study
of degradation of pressed samples of such polymers.
Shovel-shaped samples obtained by direct pressing of
PABI molding powders were exposed for three years
at the site of the Institute of Nonmetallic Materials,
Yakut Scientific Center, Siberian Division, Russian
Academy of Sciences (Yakutsk).
The initial polymer composite was as in  and
contained (wt %): PABI 97.5398.1, 4-phenyl-2,2,5,5-
tetramethyl-3-imidazoline-3-oxide-1-oxyl 1.031.5, and
carbon black 0.931.0.
The reduced viscosity at 25oC of 0.5% PABI
in concentrated formic acid was found to be 2.533
Tests were conducted in cooperation with the Institute for
Physical and Engineering Problems of the Russian North,
Yakut Scientific Center, Siberian Division, Russian Academy
of Sciences (Yakutsk).