The characterization of molecular orientation in PVC with emphasis on the use of Raman spectroscopy

A comparison is given of various methods for studying orientation in polymers, with particular reference to PVC. The Raman method and its application to PVC are described in more detail. The results of a study on PVC samples containing 0—20 pph of dioctyl sebacate plasticizer uniaxially drawn at various temperatures in the range 0 to 90°C are summarized. In this work the orientation of the crystalline regions was studied. More recent investigations are briefly discussed in which the orientation of short all-trans noncrystalline syndiotactic segments is investigated and in which Young's modulus of oriented samples is measured for correlation with the Raman data.