Accession Number : AD0438545


Title :   A STUDY OF DYNAMIC BIREFRINGENCE IN POLYMERIC SOLIDS.


Descriptive Note : Final rept.,


Corporate Author : MASSACHUSETTS UNIV AMHERST POLYMER RESEARCH INST


Personal Author(s) : Stein,Richard S


Report Date : 04 Nov 1963


Pagination or Media Count : 3


Abstract : The deformation of a polymer is accompanied by the orientation of molecules, crystals and crystalline superstructure. The case of such orientation affects the ability of the polymer to deform upon being subjected to stretch and will give rise to mechanisms of mechanical loss associated with maxima in the imaginary part of the dynamic modulus of elasticity. Tentative assignments of such loss mechanisms to molecular processes hs been previously made on the basis of dynamic mechanical studies. In the technique developed in this laboratory, birefringence (double refraction) measurements were made simultaneously with mechanical measurements. These are carried out during (a)relaxation at constant length, (b)deformation at constant strain rate, and (c)periodic strain at varying frequency. Equipment for measurements has been developed and tested. Preliminary molecular theories have been proposed. (Author, modified-PL).


Descriptors :   *POLYMERS , *REFRACTION , REFRACTIVE INDEX , DEFORMATION , CRYSTAL STRUCTURE , ELASTIC PROPERTIES , POLYETHYLENE PLASTICS , ALKENES


Distribution Statement : APPROVED FOR PUBLIC RELEASE