The Flory-Rehner approach to the swelling of polymer networks is modif
ied so as to abandon the affine deformation assumption, instead using
the assumptions of the c model of de Gennes. The resulting model, in
which the mixing term is also modified to account for hydrogen bonding
, is applied to coal networks. The results indicate that the number of
statistical segments between junction points is small and in treating
the swelling of coal networks energetic terms will probably have to b
e taken into account.