ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 4, pp. 704 !707. + Pleiades Publishing, Ltd., 2008.
Original Russian Text + N.K. Luneva, L.I. Petrovskaya, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 4, pp. 667! 671.
AND POLYMERIC MATERIALS
Performance of Intumescent Fire Retardant for Wood
N. K. Luneva and L. I. Petrovskaya
Institute of General and Inorganic Chemistry,
National Academy of Sciences of Belarus, Minsk, Belarus
Received December 6, 2007
Abstract-Performance characteristics of new fire-retardant formulations are studied, including their water
resistance and the effect of additives.
Wood has always been high among man’s pre-
ferred building materials for many reasons. It is highly
workable and has minimal environmental pollution.
However, the use of wood can be restricted by safety
requirements and regulations concerned with its ig-
nitability and fire spreading characteristics. The most
significant loss by fire falls at untreated wood con-
structions and buildings. Of course, one can raise
the fire resistance only to a certain limited extent, and
no building is completely fireproof. Until now, the
problem of wood protection against fire remains very
topical. At present, intumescent fire retardants (FRs)
are mostly used for treatment of timbers. However,
the mechanisms of chemical transformations in in-
tumescent FRs under heating still remains to be un-
derstood. The reasons are their complex composi-
tion and the fact that the main reactions occur at high
The goals of this study were to develop new green
intumescent fire retardants for wood and to examine
the effect of their composition and kind of binder
(of various viscosities) on the protective action and
water resistance. The formulations studied consisted
of polyposphorous compounds, a water-organic dis-
persion, and fire inhibitors (organic amides and poly-
ols providing expansion of the intumescent fire-re-
tardant coating). Finally, thermal degradation of
FR-treated wood was studied at 203700oC.
Therefore, we report here the properties of phos-
phorus3nitrogen-containing fire retardants: effect of
their composition on the protective action, water re-
sistance of the formulations, and thermal decompos-
ition and stability of phosphorus- and nitrogen-con-
taining compounds in FR-treated wood samples.
Among diverse organic amides and polyols, we se-
lected those whose thermal decomposition occurs
within the same temperature range as the thermal de-
gradation of wood. We used as a binder water3or-
ganic dispersions of various kinds. The components
were intimately ground and then mixed with a bind-
er for 30 min to obtain a homogeneous paste. As
samples served 30 0 60 0 150 mm wood blocks.
The FR consumption was 2703300 g m
. The fire
and water-resistance tests were performed according
to GOST (State Standard) 16 3633 98  and GOST
16 712371 , respectively.
A DTA analysis of FR-treated wood samples
(200 mg) was carried out on a Paulik3Paulik3Erdey
derivatograph at a heating rate of 20 deg min
analysis, we used sawdust (335 mm) treated with
phosphorus3nitrogen-containing formulations (wet
weight increment of the fire retardant was 170% rela-
tive to dry sawdust) and then dried to constant weight
at 45oC. The initial and heat-treated samples were
analyzed for phosphorus and nitrogen. Phosphorus was
determined photocolorimetrically , and nitrogen, by
the method described in . X-ray diffraction patterns
were obtained using a DRON-3 instrument with Cu
radiation (Ni filter) over the 2q range 2o3 60o.
Currently, phosphorus3nitrogen-containing intu-
mescent fire retardants are most widely used for wood.
We have developed high-performance green phosp-
horus3nitrogen-containing intumescent fire retardants
consisting of Craymul 2322 vinyl acetate aqueous-or-
ganic dispersion [CRAY VALLEY (Italia)], ammo-
nium phosphate, a polyol, an organic amide, and or-
ganometallic compounds . It was demonstrated that