1070-4272/04/7701-0144C2004 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 77, No. 1, 2004, pp. 144 !147. Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 1,
2004, pp. 148!151.
Original Russian Text Copyright + 2004 by Perevalova, Zheltobryukhov, Moskvichev.
AND POLYMERIC MATERIALS
Intensification of Preparation of Modified Polycaproamide Fiber
E. A. Perevalova, V. F. Zheltobryukhov, and S. M. Moskvichev
Volzhskii Polytechnic Institute, Branch of the Volgograd State Technical University,
Volzhskii, Volgograd oblast, Russia
Received February 10, 2003
Abstract-A procedure was developed for graft polymerization of dimethylaminoethyl methacrylate onto
polycaproamide using a redox system whose components are added to the reaction mixture sequentially.
A scheme of radical graft polymerization of dimethylaminoethyl methacrylate onto polycaproamide was
suggested. The properties of the copolymers were studied. The materials based on modified polycaproamide
show promise as chemisorbents.
Purposeful modification of existing macromolecu-
lar compounds is the most promising line in develop-
ment of a wide set of polymeric materials for various
purposes. One of the main procedures for chemical
modification of macromolecular compounds, including
manmade fibers, is synthesis of graft copolymers of
appropriate composition. Graft polymerization allows
wide variation of the chemical composition, structure,
and properties of polymers. Therefore, development of
highly efficient and environmentally sound processes
for production of graft copolymers derived from poly-
caproamide (PCA), one of the most abundant man-
made polymers, remains an urgent problem.
In graft polymerization onto PCA, the regular
structure of the polymer backbone remains intact ,
and the grafted polymer is distributed on the surface
of the modified fiber, which enhances the adhesive-
ness between the fibers and improves the efficiency of
the subsequent processing.
The commercially implemented procedure for pro-
duction of graft copolymers of PCA with poly(di-
methylaminoethyl methacrylate) (PDMAEMA) in the
form of KM-A1 chemisorption fiber using polycapro-
amide fiber peroxidized with atmospheric oxygen and
a solution of copper sulfate [2, 3] does not ensure
production of fibers with the sufficiently high sorption
capacity (1.031.5 mg-equiv g
); the degree of graft-
ing does not exceed 25330%.
Another procedure for preparing a PCA graft co-
polymer [4, 5] involves preliminary activation of the
polycaproamide fiber with a 0.532% solution of hy-
drogen peroxide in the presence of a copper salt
(10.2310.4 wt % Cu
relative to the reaction mixture)
at 50380oC for 30360 min. As a copper-containing
compound we used copper sulfate. The activated poly-
caproamide fiber is treated with a 20% DMAEMA
solution at 20330oC for 603120 min. After grafting
completion, the fiber is washed to remove the mono-
mer and homopolymer by treatment with ethanol in
a Soxhlet apparatus for 12 h, with subsequent drying.
The drawbacks of this procedure are relatively low
content of the grafted polymer (no more than 40 3
45%) and formation of an undesirable by-product,
PDMAEMA (homopolymer), complicating the subse-
quent processing of the fiber and decreasing the effi-
ciency of graft polymerization.
Our goal was to intensify the existing commercial
batch process. To increase the amount of the grafted
polymer and enhance the sorption capacity, we devel-
oped a procedure for preparing graft copolymers with
redox system (with copper ions intro-
duced in the form of aqueous copper sulfate solution).
The fiber was activated in steps. First, the fiber per-
oxidized with atmospheric oxygen was treated with a
copper sulfate solution, then hydrogen peroxide was
added, and the fiber activation was continued.
The raw material was ready staple polycaproamide
fiber. It is prepared from polycaproamide fiber pro-
duction waste: substandard textile and cord threads,
which are stored and, when accumulated in sufficient
amounts (approximately every 233 months), are pro-
cessed on a staple unit.
To prepare the peroxidized PCA, the starting fiber
was treated for 5 h with hot (70oC) air in a dryer.