Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 4, pp. 644−649.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
O.G. Zakharova, Yu.V. Golyagina, Yu.D. Semchikov, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 4, pp. 649−654.
AND POLYMERIC MATERIALS
Synthesis and Surface Properties of Amphiphilic Block
O. G. Zakharova, Yu. V. Golyagina, and Yu. D. Semchikov
Lobachevsky Nizhni Novgorod State University, Nizhni Novgorod, Russia
Received July 17, 2008
Abstract—Amphiphilic block copolymers of N-pyrrolidone and styrene were prepared by chain transfer to
organogermanium compounds bis(pentafluorophenyl)germane and tris(pentafluorophenyl)germane. The relative
chain-transfer constants were determined. The surface properties of the isolated block copolymers with various
numbers of units in the hydrophilic block were studied. The polar and dispersive components of the surface tension
of films of the amphiphilic block copolymers were calculated by the Zisman method.
An important trend in the progress of chemistry
and technology of polymeric materials is search for the
possibility of preparing materials with new characteristics
on the basis of the preset combination of properties of
known polymers . Of much interest in this respect is the
development of block copolymers whose macromolecules
combine blocks differing in the chemical structure and
nature. Depending on the chemical nature of blocks, their
length, number, and sequence of alternation, and also
on the tendency to crystallize, it is possible to prepare
materials whose structure and properties differ essentially
from those of the homopolymers .
Block copolymerization as a route to amphiphilic
copolymers allows the properties of hydrophobic and
hydrophilic fragments to be combined. Thanks to
advantages over common polymeric materials, block
copolymers found wide use in molecular biology,
chemical diagnostics, radioimmunotherapy, and also in
ﬁ ne chemistry; new ﬁ elds of their application are also
The most convenient and widely used procedure for
preparing block copolymers is based on chain-transfer
reactions. Chain-transfer reactions are of practical interest
for controlling the properties of polymeric materials.
It was shown previously that some perﬂ uorinated
germanium compounds are good chain-transfer agents
in polymerization of vinyl monomers .
The goal of this study was preparation of amphiphilic
block copolymers polyvinylpyrrolidone–Ge(C
polystyrene. Our study involved the following steps:
synthesis of functional polyvinylpyrrolidone (PVPD)
containing active hydrogen at the chain terminus by chain
transfer to bis(pentaﬂ uorophenyl)germane; subsequent
postpolymerization of the isolated PVPD in styrene;
characterization of the isolated amphiphilic block
copolymers and study of their surface properties.
All the monomers and solvents used in the study
were puriﬁ ed. N-Vinylpyrrolidone (VPD) was dried over
sodium sulfate. Styrene (St) was dried over CaH
distilled at reduced pressure. To prevent polymerization
in the course of distillation, we added to the monomers
an inhibitor, 2,2',6,6'-tetramethylpiperidine-1-oxyl. The
solvents used were puriﬁ ed by standard procedures .
As radical polymerization initiator we used AIBN which
was puriﬁ ed by double recrystallization from diethyl
ether. As chain-transfer agents we used bis(pentaﬂ uor
and tris(pentaﬂ uoroph
GeH, which were synthesized as
described in .
Radical polymerization of VPD was performed in
the presence of 0.005 M AIBN. The concentration of the