ISSN 1070-4272, Russian Journal of Applied Chemistry, 2014, Vol. 87, No. 5, pp. 656−663. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © V.A. Vasil’ev, I.V. Korolev, L.N. Mashlyakovskii, 2014, published in Zhurnal Prikladnoi Khimii, 2014, Vol. 87, No. 5, pp. 669−677.
AND POLYMERIC MATERIALS
Coatings based on epoxy ﬁ lm-forming agents are used
in many industries such as shipbuilding, construction, en-
gineering, etc. Chemical resistance, water resistance, heat
resistance, strength, durability are their main advantages.
Corrosion resistance of epoxy coatings is due largely
to their high adhesion to various substrates because of
the presence of polar hydroxyl groups in the structure of
epoxy oligomer. However, the presence of polar hydroxyl
groups increases the hydrophilicity of the coating, the
propensity to sorption of water and corrosive agents and,
consequently, reduces its protective properties.
The following approaches aimed at reducing the ki-
netic parameters of the diffusion of corrosive agents in the
coating are used as conventional methods of an increase in
corrosion resistance: compaction of physical and chemi-
, the introduction of ﬁ llers (nanoparticles
of various morphologies, anticorrosive pigments, etc.).
At the same time, little attention is paid to the polar-
ity of polymer coatings, which can make a signiﬁ cant
contribution to the diffusion of corrosive agents. Using
the non-polar hydrophobic polymers (ﬂ uoropolymers,
silicones) allows creation of a thermodynamic barrier to
the ingress of water and corrosive agents, however, such
coatings have low adhesion.
At the same time, the possibility to combine the prop-
erties of polar and nonpolar materials occurs and it is
implemented in so-called gradient coatings, in which the
properties of the polymer matrix can be selectively varied
along the thickness of the coating from the substrate to
the surface: from polar to non-polar.
A method based on introduction of various waterproof
additives in the paint compositions is considered as most
technologically and environmentally prospective for cre-
ation of gradient coatings. Advantages of this method are
discussed in detail in [1–3]. The concept itself consists
in migration of hydrophobic additive to the near-surface
layers of the coating in the course of ﬁ lm
and the formation of a non-polar
surface with keeping
other physical and mechanical parameters of the coating.
Among such additives those that are the most efﬁ cient
and include ﬂ
uorine-containing fragments attract great
the majority of researches relates
to liquid paint materials and data on modiﬁ cations of
powder epoxy compositions and coatings with such ad-
ditives are limited.
It should also be noted that there are currently no clear
ideas about the mechanism of the formation of gradient
ﬂ uorine-containing polymer coatings, which make pos-
Effect of Molecular Structure of Epoxy Oligomers
with Perﬂ uorinated Fragments on Hydrophobic Properties
of Powder Coatings
V. A. Vasil’ev, I. V. Korolev, and L. N. Mashlyakovskii
St. Petersburg State Technological Institute (Technical University), Moskovskii pr. 26, St. Petersburg, 190013 Russia
Received May 29, 2014
Abstract—An effect of the chemical structure of a series of the synthesized epoxy oligomers with perﬂ uorinated
fragments on the surface and mechanical properties of thermosetting powder coatings based on epoxy compositions
was investigated. The possibility of their use as modiﬁ ers for effective hydrophobic epoxy coatings with a high
level of physical and mechanical properties was demonstrated.