1976 Volume 33 Issue 8 Pages 433-439
From the analysis of angular dependence of the line shape and the second moment in NMR spectra of drawn poly (ethylene terephthalate) films, the following results have been obtained. 1) The orientation parameters which characterize the molecular orientation have been estimated for uniaxially drawn films. Those parameters for a 5.0 draw ratio film are shown to be consistent with those derived from pseudo-affine deformation model, but those for a 7.0 draw ratio film deviate from those values of the model. 2) With the approximation that the magnetic anisotropy arises only from the nearest proton pairs in a molecule and the magnetic interactions from other proton pairs are isotropic, line shapes and second moments for different structural models have been calculated. By comparison of the observed data with the calculated values, a semiquantitative measure of the orientation of the molecules was obtained, and it was shown that a biaxially drawn film exhibits approximately a preferred planar orientation in which the molecules are inclined to the plane of the film by an angle of 27-29°.
