Configurations of Polymer Molecules

The problem of the influence of intramolecular interactions on the configurations of polymer molecules has been the subject of much controversy, which need not be reviewed here. For treatment of the problem by methods other than the one presented in the following pages, the reader is referred to papers by F. Bueche, J. Chem. Phys., 21, 205 (1953), and B. H. Zimm, W. H. Stockmayer, and M. Fixman, J. Chem. Phys., 21, 1716 (1953). These papers include references to other literature on the subject. 

Casassa (S3) has modified a theory of the configuration of polymer molecules in solution due to Vrij (84) and applied it to branched molecules. If certain terms neglected in Flory s derivation are retained, Eq. (6.10) becomes ... 

Whether or not the surface of a polymer is hydrophilic or hydrophobic is not determined by whether hydrophilic or hydrophobic moieties exist in a polymer molecule but by what kind of moieties actually occupy the top surface of the polymer. Namely, the surface properties are controlled by the surface configuration but not by the configuration of polymer molecules. The configuration of PVA can be represented by -[CH2-CH(OH)] -, which indicates that the polymer is highly hydrophilic, and PVA is water soluble. However, the surface characteristics of a film of PVA depend entirely on how many OH groups exist on the top surface or buried in the bulk phase of the polymer that is described by the surface configuration. 

Chain polymers are usually plasticized for use as binders. The introduction of a plasticizer promotes good adhesion by increasing the flexibility of the film and allows more poinls of conlacl with the substrate as the solvent evaporates. The configuration of polymer molecules at the surface of a substrate will determine the number of points of contact that can be achieved. Polymer configuration is an aspect of the mechanism of coating adhesion that can be studied by Fourier transform infrared spectroscopy (see Infrared spectroscopy). 

Using the Boltzmann-Planck law, the entropy of configuration of polymer molecules can be expressed as... 

---