THE POLYMERIZATION OF A PHENOLIC BINDER
STUDIED BY ULTRASONIC METHOD
G. M. Mikhailyuk,
S. I. Borovik,
N. V. Pykhova,
T. V. Yarushina,
and S. V. Spesivtsev
Translated from Novye Ogneupory, No. 9, pp. 43 – 46, September, 2003.
Results of an ultrasonic study of the thermal polymerization of phenolic binders in periclase-carbon refractory
materials are presented. Following the change in ultrasonic velocity provides an adequate description of the
process of polymerization; optimum parameters for conducting the polymerization are determined.
In the modern steelmaking technology, heat-resistant
periclase-carbon components are used as refractory materials
for the lining of electric furnaces and steel ladles. Periclase
refractories that are prepared using a phenolic binder belong
to this type of materials.
The technology for their preparation involves the mixing
of powdered periclase and phenolic resin, molding under
pressure, and heating of green preforms at 200°C. The ther-
mal treatment causes polymerization (melting and curing) of
the binder, the composite material develop hardness which
makes it suitable for further service.
For selecting optimum heat treatment conditions of the
composite material, knowledge of the polymerization param
eters is important. These can be obtained using an ultrasonic
shadow method  based on the measurement of ultrasonic
velocities in the material under study. Our study was carried
out on cylindrical specimens 40 mm both in diameter and
height; the specimens were prepared using a fused periclase
and powdered phenolic binders of grade 012A and 0125M;
henceforth the materials prepared are denoted as SFP-1 and
To follow the change in strength properties of thermally
treated materials, an ultrasonic sounding method was used;
the method is based on the measurement of the velocity of
longitudinal ultrasonic waves propagating throughout the
specimen (Fig. 1).
The temperature of the heated specimen was measured
by means of a thermoelectric thermometer whose thermal
junction was kept in close contact with the surface of the
specimen. The time of passage of the ultrasonic signal
throughout the specimen was measured by means of a
UK-10PMS meter with an accuracy within 1.0%. The
through-the-length sounding of the specimen was done in the
longitudinal direction by means of piezoelectric transducers
at a nominal ultrasonic frequency of 60 kHz. The input and
output of ultrasonic signals was effected by means of ce-
ramic rod waveguides.
The ultrasonic velocity v,m/sec, was determined by the
v = L ´ 10
/(t – t
where L is the length of the specimen, mm; t is the time for
the passage of an ultrasonic signal throughout the specimen
and the waveguides, msec; t
is the for the passage of an ul
trasonic signal through the waveguides only, msec. The accu
racy of measurement was within 3%.
The relative ultrasonic velocity v/v
plotted as a function
of temperature for the composite materials under study is
Refractories and Industrial Ceramics Vol. 44, No. 5, 2003
1083-4877/03/4405-0346$25.00 © 2003 Plenum Publishing Corporation
Ural Electrode Institute Joint-Stock Co., Russia; Kombinat
Magnezit Joint-Stock Co., Satka, Chelyabinsk Region, Russia.
Vo l t a g e
Fig. 1. Schematic diagram of a setup for measuring ultrasonic (US)
velocities in heated specimens.