ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 1, pp. 123!127. + Pleiades Publishing, Ltd., 2008.
Original Russian Text + R.Z. Khairullin, V.P. Arkhireev, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 1, pp. 127!131.
AND POLYMERIC MATERIALS
Modification of High-Density Polyethylene
with Binary Mixtures of AA-Caprolactone and AA-Caprolactam
R. Z. Khairullin and V. P. Arkhireev
Kazan State Technological University, Kazan, Tatarstan, Russia
Received August 13, 2007
Abstract-Modification of high-density polyethylene with binary mixtures of e-caprolactone and e-caprolac-
tam was performed. The composition3property diagrams reflecting the dependences of the physicomechanical,
rheological, and optical properties of the resulting polymeric compounds on the content of modifying mixture
components were constructed, and the thermal oxidative degradation of the blend samples was studied. Based
on the results obtained, the optimal modifier concentrations were suggested.
Progress of engineering requires the development
of new types of polymeric materials with a set of
properties that are not exhibited by the known plas-
tics. This problem can be largely solved by modifica-
tion of polymers with the aim to adjust their proper-
ties to a level required by the conditions of processing
and operation. Much success has been gained in the
modification of polymers. Diverse modifying com-
pounds were tested, either as fillers or as chemically
active additives, in a wide concentration range with
virtually all the known commercial polymers .
Modification of polymers with individual com-
pounds allows improvement of many of their process-
ing and service characteristics. However, in some
cases the use of binary mixtures leads to an effect
significantly exceeding that produced by the compo-
nents taken separately, i.e., to a synergistic effect .
From this viewpoint, modification with binary sys-
tems opens wide prospects for improving the proper-
ties of polymeric materials. At the same time, it is
difficult to find among the diversity of chemical com-
pounds the components that would enhance the effect
of each other.
In this study we chose as modifying additives the
heterocyclic compounds that are capable to chemically
react with each other to form various copolymers and
with the polymer subjected to modification (high-
density polyethylene, HDPE) at temperatures close to
that of HDPE processing. The products formed in
these reactions can significantly affect the properties
of the modified polymer.
We chose HDPE as one of large-tonnage products
of polymer chemistry. In the world production of
polymerization plastics, polyethylene (PE) occupies
the first place thanks to a combination of valuable
properties with the feasibility of processing by all the
known highly productive methods used in the tech-
nology of thermoplastics. In addition, PE is one of the
cheapest polymers, which also makes its use economi-
The goal of this study was to evaluate the efficien-
cy of HDPE modification with e-caprolactam (e-CLM)
and e-caprolactone (e-CLN) taken both separately and
as binary mixtures, and also to determine the optimal
concentrations of the modifying additives.
Experiments were performed with HDPE of 277-73
brand [GOST (State Standard) 16 338385], produced
by the Organicheskii Sintez Joint-Stock Company
(Kazan) and widely used for production of various
articles. The modifying additives were e-CLN and
e-CLM, widely used as monomers for the commercial
production of the corresponding polyesters and poly-
The components were compounded in a melt on a
Brabender rotary mixer at 170oC, with simultaneous
introduction of the modifying components. Addition-
ally, 0.1 wt % 2,4-toluene diisocyanate, an activator
of anionic polymerization of e-CLN and e-CLM, was
introduced into the melt.
To optimize the search for effective compositions
of modifying mixtures, we used the simplex3lattice
experimental design . As approximating poly-
nomial we chose third- (maximal content of the addi-