Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 11, pp. 1945−1951.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © V.D. Koshevar, I.I. Goncharik, D.A. Busel, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 11, pp. 1859−1865.
AND POLYMERIC MATERIALS
Effect of the Concentration Factor and Emulsiﬁ er Nature
on the Type, Stability, and Structural-Rheological Properties
of Emulsion Based on an Epoxy Oligomer
V. D. Koshevar, I. I. Goncharik, and D. A. Busel
Institute of General and Inorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
Received December 6, 2010
Abstract—Formation conditions and structural-rheological properties of emulsions produced on the basis of ED-20
epoxy oligomer in the presence of OS-20 (B and V brands) and LCN-287 nonionogenic emulsiﬁ ers were studied.
Emulsion polymerization limitations on the chemical
composition of reagents and molecular mass of products
obtained, need to process raw materials and half-products
(resins, oligomers, lacquers) into more ecologically
perfect kinds of decorative-protective materials, and
desire to make broader the variety of ﬁ lm-forming
agents require that ways to emulsify ﬁ nished polymer
systems in water should be developed and studied. The
most widely used method for production of artiﬁ cial
latexes is emulsiﬁ cation of oligomers and solutions or
melts of polymers in aqueous media in the presence of
emulsiﬁ ers and protective colloids [1, 2]. Particularly
wide application has been gained by aqueous dispersions
of silicone, epoxy, and urethane resins [3–6].
Of fundamental importance in development
of formulations of stable aqueous dispersions and
emulsions is making the rational choice of an emulsiﬁ er
and a solvent (in the case of emulsions). One of general
principles in choosing surfactants is that they should be
adsorbed to the maximum extent at the water–oil (W/O)
or oil–water (O/W) interface. However, choice of an
effective emulsiﬁ er is always a complicated task, its
result is difﬁ cultly predictable, and it can be successfully
accomplished only upon a systematic study.
The goal of our study was to determine how the
type of epoxy oligomer emulsions and their colloidal-
chemical and technological properties depend on the
ratio between the O and W phases and on the nature
and concentration of a surfactant.
We used a technical-grade ED-20 epoxy oligomer
with a 21.5% epoxy groups, molecular mass M
400, viscosity of 17 Pa s, and epoxy number of 20 ±
1 [GOST (State Standard) 10587–84]. As emulsiﬁ ers
served nonionogenic surfactants: OS-20, a technical-
grade preparation having the form of a poly(ethylene
glycol) monoalkyl ether based on primary fatty alcohols
, where n = 18 (B brand) and 14–18
(V brand), with HLB (hydrophilic-lipophilic balance) =
16 and critical micelle concentration (CMC) of 2%
(manufactured in Russia); and also LCN-287 (Germany),
poly(ethylene glycol) alkyl ether with ethylene oxide
(70% aqueous solution, density 1.08 g cm
, Brookﬁ eld
viscosity 650 mPa s, molecular mass 1500, pH of 1%
solution 6–8, CMC = 2%).
The emulsiﬁ cation was carried out in an MPW-302
hermetically sealed homogenizer (Poland) of the disk
type at a rotation speed of 5000 rpm and temperature
of 20 ± 2°C. The emulsiﬁ cation results were assessed
by determining the type of the resulting emulsion
and its stability. A part of the emulsion was placed in
hermetically sealed graduated cylinders and the behavior
of the systems under study in the course of time was
visually inspected, with stratiﬁ cation of the system