Contribution of interferometry and mechanical parameters in evaluating molecular orientation for drawn polyester

✍ Scribed by Fouda, I M; Shabana, H M

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 144 KB
• Volume: 48
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199907)48:7<602::aid-pi193>3.0.co;2-x

✦ Synopsis

Mechanical and structural parameters related to the optical properties of polyester (PET) (woollen type) ®bres drawn at room temperature have been investigated. The changes in the strain were evaluated to obtain the molecular orientation factors hP 2 (cos u)i and hP 4 (cos u)i. From the optical orientation, the values of f 2 (u), f 4 (u) and f 6 (u) orientation parameters were calculated. The structure and properties of oriented PET have been studied in the light of the rubber elasticity theory. The dielectric constant, magnetic susceptibility, number N ' of chains between crosslinks per unit volume, optical con®guration parameter and the segment anisotropy, were among the calculated parameters. The results of the extension were used to calculate the shrinkage factor. Relationships between the calculated parameters and the draw ratios, together with micro-interferograms, are given for illustration. The present study throws light on how the applied stress changes the molecular orientation factors and the structural parameters.