THE CALCULATION OF THE PRINCIPAL POLARIZABILITIES OF POLYMER CHAINS - I
Abstract
The principal polarizabilities of polymethylene hydrocarbonds were calculated in terms of bond polarizabilities, lengths, angles, and restricted rotation potentials. A tetrahedral lattice model was used to calculate the birefringence of simple polymer chains. The polarizabilities for each configuration of the polymer were averaged for the cases of (1) equally probable orientation about the C-C bond, (2) preferred trans orientations, (3) steric hindrance, and (4) interaction between distant portions of the chain. As the energy difference between the gauch and trans positions increases, the chain tends to be more stretched out than in the equal-probability case and both the square of the displacement vector (R) and the polarizability difference increase. Depolarization of scattered light was selected over the Kerr effect as the method for studying the electric anisotropy of a small molecule. Predicted polarizabilites were higher than those from light scattering depolarization measurements. The steric effects reduced the value of R and the polarizability difference. Steric energies were obtained for each configuration corresponding to a lattice-distance interaction between the H atoms of pentane. A value of R squared - 4.5 was obtained.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 19, 1952
- Accession Number
- AD0008073
Entities
People
- Richard S. Stein
Organizations
- University of Massachusetts Amherst