Study of special birefringence in low density blown polyethylene films
Abstract:We begin by presenting a known experimental method that uses a Babinet compensator to measure the birefringence values in five samples of low density blown polyethylene thin films. Their behaviour in the determination or confirmation of the angular values of its neutral lines is anomalous, prompting the need for a theoretical model based on the framework of Jones's theory.
To make the theoretical model easier to understand and explain, we opted to present it in six stages: from the simplest unreal case — an ideal phase plate with two cross-bred linear polarizers — to the most complex real case — a real Babinet compensator with a real phase plate near both cross-bred linear polarizers. In this way we can both explain the anomalies arising in determination and confirm the exactness of the zero equations obtained to justify those solutions consistent with the experimental data.
This theoretical model explains the problem of the behaviour of birefringence measurements in low density blown polyethylene thin films and other blown polymeric materials.
Document Type: Research Article
Affiliations: Universidad Complutense de Madrid, School of Optics, Arcos de Jalón s/n. (28037) Madrid, Spain
Publication date: 2004-06-01