ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 4, pp. 665!671. + Pleiades Publishing, Inc., 2006.
Original Russian Text + Yu. V. Savel’ev, V. Ya. Veselov, L. P. Robota, O. A. Savel’eva, G. V. Chumikova, 2006, published in Zhurnal Prikladnoi Khimii,
2006, Vol. 79, No. 4, pp. 674!680.
AND POLYMERIC MATERIALS
Utilization of Unsymmetrical Dimethylhydrazine
in the Production of Polyurethanes:
Synthesis, Structure, and Properties of New Products
Yu. V. Savel’ev, V. Ya. Veselov, L. P. Robota, O. A. Savel’eva, and G. V. Chumikova
Institute of Macromolecular Chemistry, National Academy of Sciences of Ukraine, Kiev, Ukraine
Received June 16, 2005
Abstract-Unsymmetrical dimethylhydrazine is used to design novel polyurethane-based film materials,
film-forming aqueous dispersions, and closed-cell polyurethane foams.
Until recently unsymmetrical dimethylhydrazine
(UDMH) was widely used as a rocket propellant .
However, as a result of reduction of strategic arma-
ments, large amounts of UDMH have been accumu-
lated worldwide, and, because of strong toxicity, its
storage represents a danger to the environment .
The problem of UDMH utilization is still very topical,
and only a few processes exist including direct break-
down through neutralization with an electrochemically
activated solution of NaCl , introduction of UDMH
as a high-energy additive into hydrocarbon fuel, and
conversion into low-toxic compounds [4 3 6]. Presently,
processes for utilization of UDMH through conversion
into its low-toxic derivatives for various purposes are
in progress. The resulting products can be used, e.g.,
as starting reagents (precursors) in various physico-
chemical processes .
Our thought is that utilization of UDMH through
the use in production of macromolecular compounds,
e.g., polyurethanes and ionomers, shows good pros-
pects. Up to now, the efforts of utilizing UDMH in
macromolecular chemistry were directed essentially to
modification of polymers . Note here that the high
reactivity of the tertiary nitrogen atom of UDMH re-
sults in formation of hydrazinium derivatives, and
only in the cases when the quaternization of this atom
is sterically hindered, the amine hydrogen could be
reactive. Thus, the applicability of UDMH in the syn-
thesis of polyurethanes was regarded as doubtful until
In this study we examined the possibility of using
UDMH in synthesis of polyurethanes, and also the ef-
fects of the reagent ratio and process conditions on
the synthesis and properties of various types of poly-
Polyurethane elastomers. It is known that, in two-
step synthesis of a polyurethane elastomer, violation
of the stoichiometric ratio of reagents may result
in formation of a cross-linked polymer. A different
result was obtained when isocyanate prepolymer
(PP), prepared from 4,4`-diphenylmethane diisocy-
anate (DPMDI) and poly(oxytetramethylene) glycol
(PTMEG-1000), was reacted with UDMH [13, 14]. In
this case, high-molecular-weight compounds soluble
in DMF were formed with increasing mole fraction
of the prerpolymer by a factor of 2, 5, and even 10.
The polymeric films prepared from the resulting DMF
solutions demonstrated mechanical characteristics well
comparable with the traditional polyurethane elasto-
mers (Table 1).
To estimate the number-average molecular weight
of the polymers, we used the end-group analysis .
The amounts of the amide and attached hydrazide
groups were determined by potentiometric titration
in glacial acetic acid with an acetic acid solution of
. The number of nitrogen atoms in PU
samples was determined by the Kjeldahl method, and
MW (Table 2) of certain oligomers, ebullioscopically.
Such a comprehensive approach to analysis allowed
estimation of the number-average molecular weight of
the elastomers obtained and some conclusions on their
structure. As in our previous study , we noted
the formation of two types of the structure. Only at
prepolymer to UDMH ratios of 1 : (631) and 2 : 1