ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 6, pp. 1062−1069. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © L.M. Kalyuzhnaya, A.M. Bochek, I.L. Shevchuk, 2015, published in Zhurnal Prikladnoi Khimii, 2015, Vol. 88, No. 6, pp. 968−975.
Compatibility of Carboxymethyl Cellulose
with Hydroxypropyl Cellulose in Composite
Films Based on Them
L. M. Kalyuzhnaya, A. M. Bochek, and I. L. Shevchuk
Institute of Macromolecular Compounds, Russian Academy of Sciences, Bol’shoi pr. 31, St. Petersburg, 199004 Russia
Received June 10, 2015
Abstract—Sorption of water vapor by composite ﬁ lms consisting of hydroxypropyl cellulose and carboxymethyl
cellulose with different degrees of ionization was studied. The composition ranges in which the polymers are
compatible and the inﬂ uence exerted by the degree of ionization of carboxymethyl cellulose on its compatibility
with hydroxypropyl cellulose were determined. The character of the polymer–polymer–water (common solvent)
interaction in ternary systems was analyzed, and the state of sorbed water in the polymer matrix was considered
within the framework of theories of group contributions and clusterization.
Cellulose and its derivatives are semirigid-chain
polymers. Their processing to obtain ﬁ bers and ﬁ lms
is mainly performed via solution. Polymeric composite
materials with controllable properties, essentially
different from those of the initial components, can be
prepared by mixing the two polymers in a common
solvent. In so doing, it is unnecessary to use chemical
modiﬁ cation of polymers or to prepare new complex
It is known that a number of cellulose derivatives
form physical thermoreversible gels in aqueous
solutions. Among such derivatives are methyl cellulose,
hydroxypropyl cellulose (HPC), hydroxypropyl methyl
cellulose, etc. These cellulose ethers are widely used as
gel-forming agents, stabilizers, and thickeners in the food
industry, building industry, and pharmacology [1–3].
Among cellulose derivatives, HPC is of particular
interest, as it can form both thermotropic and lyotropic
liquid crystal phases of cholesteric type. The ready
availability and good solubility in water and in a number
of organic solvents made HPC a convenient object for
studying the liquid crystal (LC) ordering. However,
whereas ample data are available on LC structures of
HPC in various solvents [4–8], data on combining HPC
with other polymers are extremely scarce.
The functional properties of polymer items based
on cellulose ethers can be expanded by their further
chemical modiﬁ cation [9–12] or by combination with
other natural and synthetic polymers in solution [13–16].
Among cellulose ethers containing ionogenic groups,
carboxymethyl cellulose (CMC) has found the widest
use. It is commercially produced in the form of sodium
salt (NaCMC). This polyelectrolyte is well soluble in
water at the degree of substitution higher than 0.45–0.5.
The rheological properties and structural organization of
aqueous CMC solutions depend on the degree of CMC
ionization [17, 18]. Also, the degree of CMC ionization
inﬂ uences the compatibility of the cellulose ether with
other polymers. As shown in [19, 20], NaCMC is
incompatible with methyl cellulose and polyvinyl alcohol.
Partial compatibility of CMC with these polymers
appears at intermediate degrees of CMC ionization. For
blends of CMC with other polymers, the pattern can be
different. For example, NaCMC is partially compatible
with Poviargolum (polymeric composite of silver metal
nanoparticles stabilized with polyvinylpyrrolidone) 
and is fully compatible with poly-N-vinylformamide
(PVFA) . Conversion of NaCMC to the H form
worsens its compatibility with PVFA . It is of
scientiﬁ c and practical interest to study how the degree