  We present a simple analytical theory of flexible polymer chain dissolved in
a good solvent, carrying permanent freely oriented dipoles on the monomers. We
take into account the dipole correlations within the random phase approximation
(RPA), as well as a dielectric heterogeneity in the internal polymer volume
relative to the bulk solution. We demonstrate that the dipole correlations of
monomers can be taken into account as pairwise ones only when the polymer chain
is in a coil conformation. In this case the dipole correlations manifest
themselves through the Keesom interactions of the permanent dipoles. On the
other hand, the dielectric heterogeneity effect (dielectric mismatch effect)
leads to effective interaction between the monomers of the polymeric coil. Both
of these effects can be taken into account by the renormalizing the second
virial coefficient of the volume interactions monomer-monomer. We establish
that in the case when the solvent dielectric permittivity exceeds the
dielectric permittivity of the polymeric material, the dielectric mismatch
effect competes with the dipole attractive interactions, leading to polymer
coil expansion. In the opposite case, both the dielectric mismatch effect and
the dipole attractive interaction lead to the polymer coil collapse. We analyse
the coil-globule transition caused by the dipole correlations of monomers
within the many-body theory. We demonstrate that accounting for the dipole
correlations higher than pairwise ones smooths this pure electrostatics driven
coil-globule transition of the polymer chain.
