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

• Published in: Polymer international Vol. 48; no. 7; pp. 602 - 606
• Main Authors: Fouda, I M, Shabana, H M
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.07.1999; Wiley
• Subjects: Applied sciences; Chemical properties; Exact sciences and technology; interferometry; mechanical; mechanical, optical stress; optical stress; orientation; polyester; Polymer industry, paints, wood; Properties and testing; shrinkage; Technology of polymers; Ethylene terephthalate polymer; Drawing; Structure processing relationship; Molecular orientation; Oriented polymer; Optical properties; Ester polymer; Synthetic fiber; Property structure relationship; Measurement method; Experimental study; Interferometry
• ISSN: 0959-8103; 1097-0126
• DOI: 10.1002/(SICI)1097-0126(199907)48:7<602::AID-PI193>3.0.CO;2-X

Mechanical and structural parameters related to the optical properties of polyester (PET) (woollen type) fibres drawn at room temperature have been investigated. The changes in the strain were evaluated to obtain the molecular orientation factors 〈P2(cos θ)〉 and 〈P4(cos θ)〉. From the optical orientation, the values of f2(θ), f4(θ) and f6(θ) 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 configuration 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. © 1999 Society of Chemical Industry