ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 2, pp. 331−334. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © O.S. Ochirov, D.M. Mognonov, S.A. Stel’makh, 2015, published in Zhurnal Prikladnoi Khimii, 2015, Vol. 88, No. 2, pp. 332−335.
AND POLYMERIC MATERIALS
Based on Polyhexamethylene guanidine Hydrochloride
O. S. Ochirov, D. M. Mognonov, and S. A. Stel’makh
Baikal Institute of Nature Management, Siberian Branch, Russian Academy of Sciences,
ul. Sakh’yanovoi 8, Ulan-Ude, 670047 Russia
Received February 3, 2015
Abstract—A new method for the synthesis of hydrogels based on polyhexamethylene guanidine hydrochloride
was proposed. The use of formaldehyde as a cross linking agent for binding the terminal amino groups of the
polymer chain to form a center branch thereon underlies the method.
Production of stimulus-sensitive hydrogels is one of
the topical areas of polymer chemistry. Materials based on
polymer gels are widely used in various ﬁ elds of human
activity beginning from household chemicals and ending
by medicines [1, 2].
Polyguanidines, representatives of gelling polymers,
favorably differ from the rest of the polymers by its an-
timicrobial properties and are widely used as an active
agent of many disinfectants. Polyguanidines do not form
toxic products in water and readily decomposed with hu-
man enzyme systems, that prevents their accumulation
in the body. Polyhexamethylene guanidine (PHMG) ob-
tained by the polycondensation of hexamethylenediamine
and salts of guanidine is the main agent of disinfectants.
PHMG is prone to gelation that is due to the presence
of three-functional guanidine group, which provides a
three-dimensional crosslinked structure. However, not
all of the polymer chains of PHMG are crosslinked in 3D
structure that in the synthesis affects the yield of gels (it
reaches 45%) .
The method for the synthesis of hydrogels based on
PHMG, which includes the use of formaldehyde to bind
the terminal amino groups and allows to reach the 75%
yield of the gel, was proposed in the study.
Synthesis polyhexamethylene guanidine hydro-
chloride (PHMG). Samples of hexamethylene-diamine
(HMDA), purified by distillation, and guanidine
hydrochloride (GHC) were charged into a vial. The
reaction mixture was heated to 165°C for 3 h.
Distilled water (10 mL) and a weighted portion of
NaCl for suppressing the effects of polyelectrolyte were
added to a PHMG polymer solution of 5 mL volume
and 22.72 g L
concentration . Measurements of an
intrinsic viscosity were carried out on an Ubbelohde
viscometer in a thermostat at a constant temperature
of 25°C (Table 1). The calculation of the molecular
weight was carried out by the Mark–Kuhn–Houwink,
the constants K and α were taken from .
A number of terminal amino groups was determined
by reverse titration. To a solution (5 mL, the polymer
concentration 4.1 g L
) was added 5 mL of 0.1 N HCl,
as the control solution, a mixture of 5 mL of 0.1 N HCl,
and 5 mL of distilled water. After 0.5 h settling to the
solutions was dropwise added methyl orange indicator
(phenolphthalein may also be used). Titration was
performed till change the color of the solution from