BIREFRINGENCE OF POLYOLEFINS,
Abstract
Recently Tsvetkov3 has published birefringence curves for polypropylene fractions of differing tacticity and has shown that the more tactic samples exhibit negative birefringence but that atactic samples exhibit positive strain-birefringence both at very small strains (less than 1%). He proposes that the difference in sign of the photo-elastic contributions of the amorphous and crystalline fractions permit their separation. Measurements in this laboratory confirm Tsvetkov's experimental results. Additional measurements of the time dependence of these effects and of x-ray diffraction support a different interpretation in which the crystalline regions may contribute either positively or negatively to the birefringence. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1962
- Accession Number
- AD0420049
Entities
People
- K. Sasaguri
- Richards S. Stein
- S. Hoshino
Organizations
- University of Massachusetts Amherst