Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 10, pp. 1795−1799.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © I.P. Dobrovol’skaya, P.V. Popryadukhin, V.E. Yudin, E.N. Dresvyanina, E.M. Ivan’kova, I.V. Gofman, S.V. Kononova, 2011, published
in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 10, pp. 1703−1707.
AND POLYMERIC MATERIALS
Structure and Properties of Porous Film
Materials Based on an Aliphatic Copolyamide
I. P. Dobrovol’skaya, P. V. Popryadukhin, V. E. Yudin, E. N. Dresvyanina,
E. M. Ivan’kova, I. V. Gofman, and S. V. Kononova
Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg, Russia
Received March 29, 2011
Abstract—Phase segregation of solutions of ε-caprolactam–polyhexamethyleneadipamide copolymer in alcohol–
water mixtures and the inﬂ uence exerted on the pore structure and properties of ﬁ lm materials by the solution
concentration and time of its keeping prior to deposition were studied.
Porous ﬁ lm membranes are widely used for treatment
of liquid and gas media. Recently, in connection with the
rapid development of cell technologies, porous materials
have found use as matrices for cell proliferation and as
the base for wound coatings.
There are several ways to produce porous structure of
polymer ﬁ lms. Macroporous (pore size 0.1–10 μm) ﬁ lms
of poly(ethylene terephthalate), cellulose acetates, and
other polymers are prepared by irradiation of the material
with high-energy ions, in particular, with α-particles.
After the exposure, the ﬁ lm is treated with an alkali, which
causes additional degradation of the polymer in the zones
subjected to the action of the particles. Thus, through
channels are formed along the ion tracks. Such materials
are termed track membranes or nuclear ﬁ lters .
The preparation of a microporous structure with
the pore size of 0.01–0.08 μm and total porosity of
40–60% has been described in [2, 3]. Polyethylene ﬁ lm
is subjected to longitudinal extension by 100–300% at
room temperature, followed by thermal ﬁ xation of the
Film materials based on aliphatic copolyamides,
PVC, and poly-p-phenyleneisophthalamide, intended
for ﬁ ltration of acid and alkali solutions, including the
processes at elevated temperatures, are prepared by the
coagulation procedure [4, 5]. To this end, polymers are
dissolved in ionic liquids, the solution is applied onto
a support through a slot die, and the formed solution
is kept in air or in precipitant vapor, after which the
polymer is coagulated in a liquid precipitating medium.
The resulting ﬁ lm material has a porous structure with
a pore diameter of 40–400 μm.
In , a porous ﬁ lm material was prepared from
polyimides of various chemical structures, in particular,
from ε-caprolactam, polyhexamethyleneadipamide,
polyhexamethylenesebacamide, and ε-caprolactam–
Of most interest for forming fibers and films is
an aliphatic copolyamide (CPA), a copolymer of
ε-caprolactam with polyhexamethyleneadipamide,
because it exhibits good ﬁ lm- and ﬁ ber-forming properties
. The CPA solvent is an alcohol–water mixture,
which makes the forming process environmentally safe.
Materials made of this polymer do not contain residual
harmful solvents and preserve service characteristics in
aqueous media for a long time.
The mechanism of the pore formation in the course of
the polymer coagulation is poorly studied. Data on how
the solvent and the forming conditions (temperature,
time of solution keeping prior to deposition) affect the
pore structure and mechanical characteristics of the ﬁ lm
material are scarce.