Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 1, pp. 112−115.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
A.S. Odinokov, O.S. Bazanova, L.F. Sokolov, V.G. Barabanov, S.V. Timofeev, 2009, published in Zhurnal Prikladnoi Khimii,
2009, Vol. 82, No. 1, pp. 113−116.
AND POLYMERIC MATERIALS
Kinetics of Copolymerization of Tetraﬂ uoroethylene
with Perﬂ uoro(3,6-dioxa-4-methyl-7-octen)sulfonyl Fluoride
A. S. Odinokov, O. S. Bazanova, L. F. Sokolov, V. G. Barabanov, and S. V. Timofeev
Russian Scientiﬁ c Center “Applied Chemistry”, St. Petersburg, Russia
Public Join Stock Society “Plastpolymer”, St. Petersburg, Russia
Received November 27, 2008
Abstract—Effect of composition of a monomers mixture on the kinetics of radical polymerization in solution of
tetrafluoroethylene with perfluoro(3,6-dioxa-4-methyl-7-octene)sulfonyl fluoride is studied.
Copolymerization of tetrafluoroethylene with
perﬂ uoro(3,6-dioxa-4-methyl-7-octene)sulfonyl ﬂ uoride
(FS-141) with formation of perﬂ uorinated copolymer F-
4SF proceeds along the scheme:
The copolymerization was carried out in a steel reactor
200 ml capacity with a jacket and a frame stirrer (n =
300 rpm). The reactor temperature was maintained
with a thermostat with accuracy of ±0.1°C. Solvent was
1,1,2-triﬂ uoro-1,2,2-trichloroetane (X-113), initiator bis-
(perﬂ uorocyclohexanoyl)peroxide. Tetraﬂ uoroethylene
was puriﬁ ed from inhibitor (triethylamine) in an adsorber
ﬁ lled with activated carbon. During the experiment the
prssuere in the reactor (and hence tetraﬂ uoroethylene
concentration in liquid phase) was maintained constant by
feeding traﬂ uoroethylene from a calibrated buffer receiv-
er. The tetraﬂ uoroethylene consumption was determined
from the pressure change in the buffer receiver. The
polymer was washed with chloroform and water and
dried in a vacuum at 80°C to constant weight.
The copolymer composition was determined from
the number of sulfoﬂ uorine groups elucidated by IR
spectroscopy, elemental analysis on the content of
sulfur , and by titration of sulfonate groups of the
hydrolyzed copolymer. Molecular mass of the copolymer
was estimated from the melt flow index (MFI) using
a capillary viscometer at constant pressure (tension
2.16 kg, capillary tube diameter 2.095 mm, temperature
in the range 220−270°C).
First of all, we studied solubility of tetraﬂ uoroethylene
in FS-141 and X-113 in the working temperature range
(Figs.1 and 2).
Sulfonyl fluoride groups of the copolymer are
hydrolyzed to sulfonate ones after obtaining an extrusion
This copolymer is known since nineteen sixties. It is
used for producing the membranes for proton transmission
Naﬁ on (Du Pont, USA) and MF-4 (Russia) [1−3].
A series of patents has been published disclosing
the methods of producing ﬂ uoroplast 4SF by radical
copolymerization in solution [4-7], in bulk (without a
solvent) [7, 8] and by water emulsion method [9−17].
However, in literature there are no publications about the
kinetics of this copolymer synthesis.
The aim of this work is the study of the effect of
composition of the monomer mixture on the kinetics of
radical polymerization in solution of tetraﬂ uoroethylene