1070-4272/01/7411-1920$25.00C2001 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 74, No. 11, 2001, pp. 1920!1923. Translated from Zhurnal Prikladnoi Khimii, Vol. 74, No. 11,
2001, pp. 1859!1862.
Original Russian Text Copyright + 2001 by Starostina, Khasbiullin, Stoyanov, Chalykh.
AND POLYMERIC MATERIALS
Acid!Base Interactions at the Modified
I. A. Starostina, R. R. Khasbiullin, O. V. Stoyanov, and A. E. Chalykh
Kazan State Technological University, Kazan, Tatarstan, Russia
Institute of Physical Chemistry, Russian Academy of Sciences, Moscow, Russia
Received April 18, 2000; in final form, March 2001
Abstract-The acidity parameters of metal and polymeric surfaces were determined as influenced by the
extent of surface oxidation of metals and by the modifier content in the polymer.
Acid3base interphase bonds, including hydrogen
bonds, are considered at present as factors largely
responsible for adhesion .
To evaluate the interaction of solids with a wetting
liquid and of polymer layers with supports, data on
the acidity and basicity of compounds involved are
required. In this connection, procedures for measuring
surface properties by gas chromatography, flow micro-
calorimetry, ellipsometry, and NMR and IR spec-
troscopy are actively developed .
Berger  proposed a simple and convenient proce-
dure for determining the surface acidity of polymers
and metals by measuring the contact angle between
the surface and reference liquids.
Estimation of the adhesive properties of a material
from its surface acidity is of special interest. The
correlation between the strength of adhesion joints and
the acid3base properties of adhesives and adherents
was observed in many works .
Correct determination of the acidity of any smooth
solid surfaces, increase in adhesion of a polymer to
the metal surface by variation of this parameter, and
prediction of the interface interactions in actual sys-
tems are urgent problems.
The aim of this work was to study the nature of
interface interactions in corrosion-protective coatings
of various polyethylenes (PEs) modified with various
additives and to determine the main relationships of
the acid3base interactions occurring in modified PEs
during formation of their coatings.
In this work we used the following materials:
powdered (particle diameter less than 315 mm) non-
stabilized high-density polyethylene (HDPE) prepared
by the gas-phase procedure [for pipe production,
GOST (State Standard) 16338385]; powdered (par-
ticle diameter less than 315 mm) nonstabilized low-
density polyethylene (LDPE) of 168033 070 trade
mark [GOST (State Standard) 16337377]; primary
aromatic amines (PAAs) [4,4`-diamino-3,3`-dichloro-
diphenylmethane (DC), polyamine T, and o-phenyl-
enediamine (o-PDA)] and phenols [diphenylolpropane
(DPP) and pyrocatechol] as modifiers; N,N`-m-phenyl-
endimaleinimide (PDMI) and dithiodiphenylenedi-
maleinimide (TPDMI) as cross-linking agents. The
supports were made of steels of various types, copper,
aluminum, titanium, zinc, brass, etc.
The procedure for preparing PE3modifier com-
posites and PE coatings on metal supports are de-
scribed in our previous works .
The surface acidity was estimated by the Berger’s
procedure . Cosines of the contact angles of six
reference liquids with the tested surface were deter-
mined with a KM-8 cathetometer. The thermodynamic
work of adhesion for each liquid W
by the equation
(1 + cosG),
is the total free surface energy of the refer-
The values of g
are presented in Table 1. W
was calculated from the measured cosines of angles
between the reference liquids and the surface. The
geometric mean of the total free surface energy of the
was determined by graphic solution of
the Owens3Wendt equation
(1 + cosG)/2 = (C