Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 4, pp. 622−629.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
A.K. D’yakova, S.A. Trifonov, E.A. Sosnov, A.A. Malygin, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 4,
AND POLYMERIC MATERIALS
Effect of Chemical Modiﬁ cation on Structural and Energy
Characteristics of the Surface of Polyethylene and Polyvinyl
A. K. D’yakova, S. A. Trifonov, E. A. Sosnov, and A. A. Malygin
St. Petersburg State Institute of Technology (Technical University), St. Petersburg, Russia
Received December 30, 2008
Abstract—The possibility of controlling the surface energy and wettability of polyvinyl chloride and polyethylene
films by chemical gas-phase modification was studied. The surface of the initial and chemically modified polymeric
materials was examined by atomic force microscopy.
Polyethylene and polyvinyl chloride (PVC) are among
the most widely used polymers today, owing to good
dielectric characteristics, high chemical resistance, and
strength. These materials are vinyl polymers with the
repeating unit [–CH
, with one of the hydrogen
atoms in PVC substituted by the chlorine atoms. However,
in many cases the use of these materials is considerably
restricted because of their low surface energy, which leads
to poor adhesion and low wettability of the surface. These
properties largely depend on the chemical composition
and structure of the surface layer and can be controlled by
two main methods: removal of weak boundary layers of
the polymer and formation of new active centers altering
the surface energy [1, 2].
One of the methods for forming new functional
structures on the surface of polymeric materials is
gas-phase modiﬁ cation of matrices using principles of
molecular layering (ML) . This method consists in
performing chemical reactions between externally supplied
reagents and the functional groups of the support under
essentially nonequilibrium conditions. The ML technique
proved to be very efﬁ cient for controlling the macroscopic
properties of phenol–formaldehyde, polyamide, epoxy,
and other polymeric materials. According to the results
of IR studies, chemical modiﬁ cation involves grafting of
element-containing structures to surface reaction centers
of polymers (double bonds, oxygen-containing groups,
hydrogen at tertiary carbon atom), which leads to changes
in the thermal oxidation, electret, diffusion, and other
properties of materials [4–7].
In this study we examined how the chemical
composition of polyvinyl chloride and low-density
polyethylene (LDPE) ﬁ lms modiﬁ ed with vapors of
volatile halides [PCl
, and Si(CH
affects the energy characteristics, wettability, and
topography of the polymer surface.
The effect of chemical modiﬁ cation was studied with
ﬁ lms of low-density polyethylene of 158-03-020 grade
and Pentaprint polyvinyl chloride. The functional use
of these materials is largely determined by the energy
characteristics, including the wettability of the surface.
As modifying agents we chose low-boiling halides of
phosphorus, vanadium, titanium, and silicon.
The sample modiﬁ cation was performed in a ﬂ ow-
type reactor under the conditions described in [4, 6].
According to the results of chemical analysis, the content
of modifying elements in the polymer ﬁ lms is about 10
[8, 9]. Presumably, chemical modiﬁ cation
of the polymeric materials results in formation in their
surface layer of element–hydroxyl, element–oxygen, and