AND POLYMERIC MATERIALS
Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 11, pp. 1798−1804.
Pleiades Publishing, Ltd., 2013.
Original English Text © Rashid Saleem, Ahmad Adnan, Fahim Ashraf Qureshi, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 11,
Study of Viscosity Behavior and Retanning Properties
of Sulfonated Glutaric Dihydrazide Formaldehyde Condensate
under Different Reactant Ratios
, Ahmad Adnan
, and Fahim Ashraf Qureshi
Department of Chemistry, GC University, Lahore, 54000 Pakistan
Comsats Institute of Information Technology, Islamabad, 45600 Pakistan
Received November 12, 2013
Abstract—Sulfonated glutaric dihydrazide formaldehyde condensates with less than 0.05% free formaldehyde
were prepared through controlled reaction of glutaric dihydrazide, sodium metabisulﬁ te, and formaldehyde in three
processing steps. Mole ratio of sodium metabisulﬁ te/glutaric dihydrazide (S/GDH) was varied from 0.1 to 0.5 and
that of formaldehyde/glutaric dihydrazide (F/GDH) from 1 to 3. The effects on viscosity and ﬂ uidity of resins were
observed with varying degrees of sulfonation and changeable mole ratio of formaldehyde/glutaric dihydrazide.
Viscosity of resins showed increasing trend with increasing mole ratio of formaldehyde/glutaric dihydrazide and
decreasing trend with increasing mole ratio of sodium metabisulﬁ te/glutaric dihydrazide. Increase in viscosity of
resins was due to increase in molecular weight of polymer chains. After gaining a critical molecular weight dur-
ing condensation, resins turned into gel form. The resins were comparatively applied on chrome tanned cow hide
against commercial sulfonated urea formaldehyde powder resin (Resin UFT).
Basic chromium sulfate (chrome) is one of the most
famous tanning agents used all over the world repre-
senting 80% of leather production . Basic chromium
sulfate tanned leathers have high tensile strength and light
weight . Chromium has crosslinking ability with the
acidic amino groups of collagen through coordination
bonds. Physical and mechanical property of leather is
improved after crosslinking with chromium .
ever, in suede leathers, course nap and lack of fullness
are some disadvantages of the basic chromium sulfate
tanned leather. Additionally, hexavalent chromium has
been determined in mixture of Cr (VI) and Cr (III) in
few Egyptians tanning industries in wet ﬁ nishing baths
When basic chromium sulfate is used as a tanning
agent in leather processing, about 70% of total chromium
reacts with hides and 30% of chromium remains in solid
waste. Recovery of waste chromium and its utilization is
signiﬁ cant for the development of the leather industry .
Different types of retanning agents have been devel-
oped to improve properties of chrome tanned leather.
In vegetable retanning, mimosa and chestnut extracts
are used. Synthetic organic tanning agents include alde-
hydes, their derivatives, and polymers of different types
like urethane, melamine, and acrylate resins . Leather
tanned with glutaraldehyde goes into yellowish orange
color, which is usually not desirable in leather. Several
endeavors have been made to transform the chemistry for
anticipation of color development, but none was found
to be absolutely successful . Sulfonated urea phenol
condensed polymers are used in combination with ferrous
sulfate as tanning agents which enhanced the shrinkage
temperature of the leather up to 90°C . Sulfonated
melamine and urea formaldehyde resins show sensitivity
to pH ﬂ uctuations and form precipitates on leather surface
 during retanning process and lose their tanning action.
Urea formaldehyde resin is accepted in many engi-