Polyurethane Varnish Materials Based
S. E. Mitrofanova, I. N. Bakirova, L. A. Zenitova, A. R. Galimzyanova, and E. S. Nefed’ev
Kazan State University of Technology, Kazan, Tatarstan, Russia
Received March 10, 2009
Abstract—Polyurethane varnish materials based on diphenylolpropane were synthesized. The properties of the
varnishes and coatings obtained were studied in relation to the nature and ratio of the starting compounds.
AND POLYMERIC MATERIALS
ISSN 1070-4272, Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 9, pp. 1630–1635. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © S.E. Mitrofanova, I.N. Bakirova, L.A. Zenitova, A.R. Galimzyanova, E.S. Nefed’ev, 2009, published in Zhurnal Prikladnoi Khimii,
2009, Vol. 82, No. 9, pp. 1529–1534.
The modern paint-and-varnish industry offers a
wide assortment of coatings, among which a particular
place is occupied by compounds based on poly-
urethane (PU) film-forming components. The volume
of production and consumption of these materials is
lower compared to other types of varnishes and paints,
but the production growth rate is higher by a factor of
almost 2. According to experts’ forecast, in the nearest
future the demand for these materials will increase, on
the average, by 4–6% annually .
Such a demand for PU varnish materials (VMs) is
due to a unique set of service properties characteristic
of PU coatings. They exhibit extremely high wear
resistance, excellent adhesion to metal and nonmetal
surfaces, high strength, and resistance to atmospheric
factors, water, chemicals, benzine, and oil .
At the same time, the available assortment of VMs
allows preparation of coatings that either have high
hardness but are brittle and therefore have poor impact
resistance or, vice versa, are insufficiently hard and
therefore have poor abrasive resistance. There are
virtually no formulations ensuring formation of films
that would combine hardness and elasticity.
Furthermore, in most cases the raw materials used in
the synthesis are expensive and toxic and are in short
supply. This particularly concerns such compounds as
1,4-butanediol and methylenebis-o-chloroaniline (MOCA)
acting as chain-extension and curing agents.
The goal of this study is the preparation of high-
quality coatings using new raw materials and
evaluation of the properties of these coatings.
In our study we used polyoxypropylenetriols of
molecular weights 3000, 3600, and 5000 derived from
glycerol: Laprol 3003 [TU (Technical Specification) 6-
05-1513–75], 3603 (TU 6-05-2033–87), and 5003 (TU
6-55-62–93) grade, with OH group content of 1.70,
1.42, and 1.02 wt %, respectively; diphenylolpropane
(DPP), bp 250–252°C/13 mm Hg, mp 155°C (TU
2423-172-00203335–2007); 1,4-butanediol (BD), mp
20.9°C, bp 203°C/759 mm Hg (TU 64-5-105–86);
polyisocyanate (PIC), NCO group content 30 wt %;
distilled phenyl isocyanate (PhIC), bp 343°C/3 mm
1.5367; distilled triethylamine (TEA), bp 89.5°C,
1.4044; pure grade acetone.
The model compounds, product 1 (DPP + 2PhIC)
and product 2 (BD + 2PhIC), were synthesized by the
reaction in acetone of DPP or BD with 2 mol of PhIC
in the presence of catalytic amounts of TEA . The
products obtained were analyzed by IR spectroscopy
on a Vector 22 Fourier spectrometer (Bruker) with a
resolution of 4 cm
, and also on an SDT Q 600
thermal analyzer at a heating rate of 2 deg min
temperature range 25–300°C.
Polyurethane varnish was synthesized at room
temperature. The reactant amounts were taken so as to
ensure the molar ratio NCO : OH = 1 : 1. Coatings
were prepared by casting a varnish compound onto
glass, steel, or tin plates.
The conventional viscosity of VMs was determined
as outflow time from a VZ-4 viscometer in accordance