The bending recovery of polymer films. I. A phenomenological model
| Autor: | W. A. Chen, Andy H. Tsou, Jehuda Greener, K. C. Ng |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
chemistry.chemical_classification
Materials science Polymers and Plastics Drop (liquid) Bent molecular geometry Mechanics Polymer Condensed Matter Physics Curvature Simple extension Spectral line chemistry Phenomenological model Materials Chemistry Physical and Theoretical Chemistry Composite material Temporal shift |
| Zdroj: | Journal of Polymer Science Part B: Polymer Physics. 29:843-858 |
| ISSN: | 1099-0488 0887-6266 |
| DOI: | 10.1002/polb.1991.090290709 |
| Popis: | When a flat film is bent to some fixed curvature, held at this state for some time, and then released, its curvature is usually observed to drop instantaneously to some finite value and then gradually decrease with time. This phenomenon, generally referred to as bending recovery, has been modeled by simple extension of the classical plate-bending theory to linear-viscoelastic materials. The model assumes that the relaxation spectra in tension and compression are dissimilar but are interrelated through a simple temporal shift. Experimental data, including instantaneous recovery at ambient and elevated temperatures as well as recovery over extended times, have been generated for four films with widely different relaxation characteristics. The data are in reasonable agreement with predictions of the model if a constant value of the compressive shift parameter (see text) is used for all materials. The model indicates that the bending recovery of a polymer film is intimately related to its relaxation spectrum and can be effectively manipulated by changes in temperature and winding time. |
| Databáze: | OpenAIRE |
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