ISSN 1070-4272, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 2, pp. 300!304. C Pleiades Publishing, Ltd., 2007.
Original Russian Text C N.M. Zabivalova, A.M. Bochek, E.N. Vlasova, B.Z. Volchek, 2007, published in Zhurnal Prikladnoi Khimii, 2007, Vol. 80,
No. 2, pp. 301!305.
AND POLYMERIC MATERIALS
Preparation of Mixed Cellulose Ethers by the Reaction
of Short Flax Fibers and Cotton Linter
N. M. Zabivalova, A. M. Bochek, E. N. Vlasova, and B. Z. Volchek
Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg, Russia
Received July 3, 2006; in final form, October 2006
Abstract-The conditions of preparation of mixed cellulose ethers containing carboxy and amino groups
by the reaction of samples of short flax fiber and cotton linter with monochloroacetamide were examined.
The influence of the amino groups of the mixed cellulose ethers on the rheological properties of their
aqueous solutions was elucidated.
An increased interest is presently attracted by self-
associated polymer systems based on biodegradable
and environmentally safe natural polymers. These sys-
tems include water-soluble compounds of cellulose
and, in particular, its ethers: carboxymethyl cellulose
in the form of a sodium salt (NaCMC), methyl cel-
lulose (MC), hydroxyethyl cellulose (HEC), methoxy-
propyl cellulose, etc. Most of the above-mentioned
ethers possess a set of valuable properties: water sol-
ubility, lack of toxicity, and good thickening power.
They find wide application in food industry, perfum-
ery, oil extraction, and medicine . The principal
raw materials for preparation of the ethers are wood
and cotton varieties of cellulose. Large-capacity waste
from flax production, short flax fibers and the hard-
wood part of the flax stem (flax boon) can serve as
an alternative source of cellulose for preparation of
its various ethers.
Among ionic compounds of cellulose, the most ex-
tensively used is carboxymethyl cellulose; it serves as
a thickening and structuring agent in production of ad-
hesives, lacquers, paints, detergents, and toothpastes.
Chemical modification of CMC is one of the ways to
modify the properties of this widespread ether. Intro-
duction of new functional groups (in this case, amide)
into CMC macromolecules implies changing the phys-
icochemical properties of a new cellulose compound.
The physicochemical properties of the resulting
ether are influenced by the nature of the initial poly-
mer, namely, the molecular weight, chemical com-
position, presence of associated substances, structural
uniformity, and fiber morphology.
Here, we examined the conditions of synthesis of
cellulose ethers by the reaction of cotton and flax
cellulose with monochloroacetamide (MCAA). It can
be assumed that new cellulose compounds contain-
ing carboxy and amide groups exhibit ion-exchanging
Carboxymethyl cellulose amides (CMCAs) can be
prepared by the reaction of CMC acid chlorides with
amines [23 4] and by the reaction of CMC in the acid
form (HCMC) with amines . By contrast to
the above-mentioned methods of preparation of
CMCAs, we studied here the conditions of synthesis
without employing high temperatures and such re-
agents as dimethylformamide, SOCl
, benzene, and
xylene. The synthesis conditions and the apparatus
in our experiments were identical to those in prepara-
tion of NaCMC.
As initial materials served cotton linter with a de-
gree of polymerization DP
= 1500 and pretreated
short flax fibers with DP
= 3700. The flax fibers
were treated by boiling for 3 h in the cooking solu-
tion of composition NaOH : Na
O (at a fi-
ber : NaOH : Na
ratio of 1 : 1.2 : 0.7) in a nitro-
gen medium . Such a treatment removes most of
associated substances (hemicelluloses, lignin, pectins)