1070-4272/05/7811-1884C2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 11, 2005, pp. 1884!1887. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 11,
2005, pp. 1917!1920.
Original Russian Text Copyright C 2005 by Galibeev, Mukhametzyanova, Kochnev, Arkhireev, Gnezdilov.
AND POLYMERIC MATERIALS
Copolymerization of Chlorine-Substituted Monoisocyanates
with A-Caprolactone in the Presence of Sodium Caprolactamate
S. S. Galibeev, A. M. Mukhametzyanova, A. M. Kochnev,
V. P. Arkhireev, and O. I. Gnezdilov
Kazan State Technological University, Kazan, Tatarstan, Russia
Received August 17, 2005
Abstract-Copolymerization of e-caprolactone with a series of aromatic chlorine-substituted monoisocyanates
in the presence of catalytic amounts of sodium caprolactamate was performed. The structures of the products
obtained and their macromolecular characteristics were determined by IR and
H NMR spectroscopy and by
gel permeation chromatography; kinetic and thermodynamic relationships of the process were found.
Previously we demonstrated the possibility of
copolymerization of phenyl isocyanate (PIC) with
e-caprolactone (e-CLN) in the presence of a catalyst
(sodium caprolactamate, Na-CL) and an activator
(2,4-toluylene diisocyanate, TDI) . The reaction
mainly yielded alternating copolymers, and its rate
largely depended on the comonomer ratio, growing
with an increase in the content of the isocyanate com-
ponent. Our IR and
H NMR study  showed that
the copolymerization of e-CLN with isocyanates oc-
curs via cleavage of the N=C bond in isocyanates and
acyl bond in the lactone; the resulting copolymer has
the following structure:
To extend the range of the isocyanates used and
confirm the possibility of preparing alternating co-
polymers, we performed in this study the copolymeri-
zation of e-CLN with chlorine-substituted monoiso-
cyanates: 3-chlorophenyl isocyanate (3-CPI) and
4-chlorophenyl isocyanate (4-CPI).
e-CLN and 3-CPI (Fluka) were vacuum-distilled
before use; 4-CPI (Fluka) was used without additional
As catalyst we used sodium caprolactamate (Na-
CL) prepared by the reaction of sodium metal with
e-caprolactam (e-CL) in the bulk at 1103120oC. The
product was stored in a desiccator under an inert gas.
The Na-CL content in the product was 25 wt %.
The syntheses of the copolymers were performed in
an argon flow in a three-necked flask equipped with
a reflux condenser and a stirrer. The polymerization
was carried out as follows: 1 wt % Na-CL was dis-
solved in e-CLN at 80oC, after which the calculated
amount of isocyanate was added with continuous stir-
ring, and 1 wt % activator (TDI) was added. The
products were purified by tenfold reprecipitation with
hexane from acetone.
The chemical structures of the products formed in
the reactions of monoisocyanates with e-CLN were
studied by IR Fourier spectroscopy on a Perkin3Elmer
PC-16 spectrometer and by
H NMR spectroscopy on
a Bruker MSL-400 spectrometer (400 MHz) with
as solvent and reference.
Gel chromatographic studies were performed with
a Waters 150C gel chromatograph equipped with
Ultrastyrogel HR 10
A columns; the solvent was
DMF, and the reference, polystyrene.
The content of isocyanate groups was determined
by potentiometric titration according to . The reac-
tion rate constants and the activation energy and en-
tropy were determined according to . The copoly-
merization constants were calculated by the Fineman3
Ross method .
As compared to the spectra of the starting mono-
H NMR spectrum of the product of copoly-
merization of e-CLN with 3-CPI contains a signal at
2.432.2 ppm corresponding to the a-CH
ative to the carbonyl group of the opened lactone ring
and a signal at 4.333.9 ppm corresponding to the
protons relative to the ester oxygen atom. The