SCIENTIFIC RESEARCH AND DEVELOPMENTS
A MECHANISM FOR PHOSPHATE HARDENING AND PROSPECTS
FOR THE USE OF METAL PHOSPHATE MATERIALS (A REVIEW).
PART I. THE NATURE OF HYDROGEN BONDING AND ITS FUNCTION
IN THE MECHANISM OF PHOSPHATE HARDENING
I. A. Karpukhin,
V. S. Vladimirov,
and S. E. Moizis
Translated from Novye Ogneupory, No. 12, pp. 54 – 61, December, 2004.
Original article submitted July 12, 2004.
The physical chemistry of multistep hardening of phosphate bonding materials is considered. The function of
hydrogen bonds in the phosphate hardening mechanism and their effect on the adhesive properties of phos-
phate bonding materials are discussed. Techniques for enhancing the adhesive properties of phosphate binders
using powdered oxides, hydroxides, and salts and their involvement in acid-base reactions are considered.
Bonding materials for nonfired refractories, corrosion-resistance coatings and mortars, and areas for their po-
tential applications are proposed.
Inorganic bonding agents (binders) have gained accep-
tance in the production of building materials and refractories
owing to their property, when mixed with water or aqueous
acid-base solutions and initially persisting as viscous or
paste-like mixes, to convert to monolithic, easily shaped ma
terials. In recent years, the need for bonding materials with
superior adhesive properties to metals, ceramics, refractories,
and glass and capable of providing protection from corrosion
The conventional binders, classified in terms of the hard
ening mechanism, can be divided into two groups: (i) of
hydration type and (ii) physicochemical type. The former
type includes cements (including high-alumina ones), plaster
(gypsum), lime, and similar materials. These materials
harden with some water added to them via hydration of cal
cium oxide (lime) to yield saturated calcium hydroxide solu
tions; as part of the water vaporizes, the rest of the water be
comes bound into crystal hydrates to form cement stone. The
cement hardening mechanism is controlled by a range of fac
tors such as dispersivity, specific surface, and sorptive capac
ity of the components displaying hydration properties.
The binding systems with a hardening mechanism con-
trolled by physicochemical factors (primarily acid-base in-
teractions) include mostly phosphate binders, in particular,
dissolved metal phosphate binding solutions. Phosphate
binders are typically available as aqueous solutions of phos
phoric acids and their salts. The structural formula of
orthophosphoric acid may be represented as
In the H
molecule, one of the oxygen atoms is
linked via a double bond to the central phosphorus atom.
This specific feature imparts the property of polycon
densation and polymerization with phosphorus compounds
. The polycondensation of monophosphoric acid at
step 1 results in the formation of a dimer, pyrophosphoric
Refractories and Industrial Ceramics Vol. 46, No. 3, 2005
1083-4877/05/4603-0180 © 2005 Springer Science+Business Media, Inc.
MaVR Research and Production Trading Firm, Zhukovskii, Mos
cow Region, Russia.
HO – P – HO.