Accession Number : ADA328045

Title :   An Experimental Investigation of Electromechanical Response in Polyurethane Elastomer (Dow 2103-80AE).

Descriptive Note : Final technical rept. 1 Jul 95-30 Jul 97,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK MATERIALS RESEARCH LAB

Personal Author(s) : Zhang, Qiming

PDF Url : ADA328045

Report Date : 01 AUG 1997

Pagination or Media Count : 52

Abstract : In this program, the electric field induced strain response and other related material properties for the polyurethane elastomer (Dow 2103-80AE), which was reported to exhibit a giant strain response, were investigated. We show that the observed large field induced strain is only a thin film effect and in bulk samples, the electromechanical response is not significant. To understand how various effects influence the electromechanical response in this type of material, we examined the material properties in both bulk samples and thin films. In bulk samples, we show that the polymer chain segment motions can be divided into those responsible for the mechanical, those for the polarization (dielectric), and those for both (electromechanical). By molecular engineering, one should be able to selectively enhance different type of the chain segment motions for different applications. Although a great deal of efforts have been devoted to the characterization of the field induced strain response in thin and soft samples, there was no existing device which is capable of measuring the strain in thin polymer samples reliably and conveniently. To overcome this difficult, a novel bimorph based dilatometer was developed for the strain measurement in thin and soft polymer films, which exhibits a high resolution, reliability, and great convenience. Based on the experimental results on thin films samples, we conclude that the space charge injection, which results in a non-uniform charge distribution and hence, a non-uniform electric field distribution across the sample thickness, is responsible for the large field induced strain response observed in thin film samples.

Descriptors :   *ELASTOMERS, *STRAIN(MECHANICS), *POLYURETHANE RESINS, POLARIZATION, THIN FILMS, COPOLYMERS, HIGH RESOLUTION, PIEZOELECTRICITY, STRAIN GAGES, CHARGE TRANSFER, ELECTROSTRICTION, SPACE CHARGE.

Subject Categories : Elastomers and Rubber
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE