Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 11, pp. 17641770.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © S.V. Kudashev, U.R. Urmantsev, G.V. Selezneva, N.A. Rakhimova, V.F. Zheltobryukhov, 2012, published in Zhurnal Prikladnoi
Khimii, 2012, Vol. 85, No. 11, pp. 18601866.
AND POLYMERIC MATERIALS
Surface Modiﬁ cation of Granules of Polyethylene
Terephthalate by Fluorine-Containing Urethanes
S. V. Kudashev
, U. R. Urmantsev
, G. V. Selezneva
N. A. Rakhimova
, and V. F. Zheltobryukhov
Volgogtrad State Technical University, Volgograd, Russia
JSC “POLIES”, Blagoveshchensk, Bashkortostan, Russia
Received April 16, 2012
Abstract—The possibility of surface modiﬁ cation of polyethylene terephthalate granulate by ﬂ uorinated prepoly-
mers which contain urethane groups was examined. A depth of a modiﬁ ed surface layer (12–18 m) was found.
The modiﬁ ed system reduces a crystallinity of a polymer and varies thermal transitions, which characterize a
mobility of structural units of a macromolecular chain. An increase in hydrolytic and thermal-oxidative stability
of the modiﬁ ed polyethylene terephthalate was demonstrated.
Modiﬁ cation of polymers for obtaining materials with
new or improved properties attracts constant interest of
researchers, because the raw materials often have no a set
of properties and characteristics required for a particular
practical application. The use of polyethylene terephthal-
ate (PET) for production of materials of broad-purpose
application requires universal methods to stabilize the
polyester, which can not be achieved at the present time
using a variety of organic and inorganic modiﬁ ers [1–3].
Poly- and perﬂ uorinated compounds for this purpose
are of great interest, as it allows to make signiﬁ cant im-
provements in a number of properties (heat, light, wear
resistance, hydrolytic stability) of heteropolymers even at
their low content (10
–5 wt %) [4, 5]. At the same time,
the use of ﬂ uorinated diols in the synthesis of modiﬁ ed
PET leads to the fact that they are poorly esteriﬁ ed by
acids. This impedes meaningful industrial synthesis of
polyester having an improved set of properties .
A goal of the study is to investigate features of the
surface modiﬁ cation of PET granulate by ﬂ uorinated
urethanes for synthesis of polyester with improved hy-
drolytic and thermo-oxidative stability.
High-viscosity PET granulate with an average grain
size of 3 × 3 mm (JSC “POLYEF,” Blagoveshchensk,
Bashkortostan) with carboxyl terminal group content
of 30 mmol kg
(TU 2226-008-39989731-2009) was
used as the polyester. For modiﬁ cation of the polyester
ﬂ uorine-containing urethanes (FU) were used in the
form of a mixture of prepolymers prepared by reacting
at the same time of 4,4'-diphenylmethane diisocyanate
with 1,1,5-trihydroperﬂ uoropentanol-1 .
Surface modiﬁ cation of PET pellets in a FU
concentration range of 0.5–3.0 wt % was performed by
using a solution of chlorobenzene (analytical purity).
Granulated PET (100 g), FU (2 g), and 300 ml of
chlorobenzene were placed in a glass ﬂ ask. The ﬂ ask
was incubated at 120°C for 4 h and then the solvent was
distilled off. The surface-modiﬁ ed PET granulate were
dried at 100°C under a vacuum.
The surface-modiﬁ ed PET pellets were examined by
FTIR spectroscopy (Nicolet-6700 spectrophotometer),
thermogravimetry (TGA) in air (derivatograph Q-1000,
MOM, Hungary), differential scanning calorimetry (DSC
calorimeter Netzsch DSC 204 F1 Phoenix, Germany), as
well as atomic force scanning probe microscopy (AFM
microscope Solver PRO with silicon probes with stiffness
40 N m
and a radius of curvature of a needle of 10 nm). A
weighted sample for recording TGA and DSC curves was
16–20 mg, a rate of rise of temperature was 10 deg min