Conformation of polymer chains

Changes in the conformation of polymer chain backbone occur much more slowly in the vicinity of Tg than most of the molecular processes that serve as examples of simpler equilibria. 

Semiyen, J. A. Ring-Chain Equilibria and the Conformations of Polymer Chains. Vol. 21, pp. 41—75. 

The conformation of polymer chains in an ultra-thin film has been an attractive subject in the field of polymer physics. The chain conformation has been extensively discussed theoretically and experimentally [6-11] however, the experimental technique to study an ultra-thin film is limited because it is difficult to obtain a signal from a specimen due to the low sample volume. The conformation of polymer chains in an ultra-thin film has been examined by small angle neutron scattering (SANS), and contradictory results have been reported. With decreasing film thickness, the radius of gyration, Rg, parallel to the film plane increases when the thickness is less than the unperturbed chain dimension in the bulk state [12-14]. On the other hand, Jones et al. reported that a polystyrene chain in an ultra-thin film takes a Gaussian conformation with a similar in-plane Rg to that in the bulk state [15, 16]. 

Probabilities of equilibrium conformations of polymer chains are describ-able by the Gaussian statistics. 

Cooper, D. R. and Semiyen, J. A., Equilibrium ring concentrations and the statistical conformations of polymer chains part 11. Cyclics in polyethylene terephthalate), Polymer, 14, 185 (1973). 

Polymer reactivity can also be affected by the conformation of polymer chains [Imanishi, 1979 Overberger et al., 1973 Overberger and Morimoto, 1971 Pshezetsky et al., 1968], Whether the polymer chain exists in a tight or expanded coil can influence the accessibility of polymer functional groups and the local concentration of a small-molecule reactant. 

The structure of polymer solutions and the concepts of De Gennes on the conformation of polymer chains in solution and in melts... 

Semiyen, J. A. Ring-Chain Equilibria and the Conformations of Polymer Chains. Vol. 21, pp. 41-75. Sharkey, W. H. Polymerizations Through the Carbon-Sulphur Double Bond. Vol. 17, pp. 73-103. Shibaev, V. P. and Plati, N. A. Thermotropic Liquid-Crystalline Polymers with Mesogenic Side Groups. Vol. 60/bi, pp. 173-252. 

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