| Electrostriction is strain produced by the electric field which has quadratic dependence on the electric field. Scientists showed interest in electrostriction of rubber as early as 1820's. The discovery of useful piezoelectric and pyroelectric effects of poly(vinylidene fluoride) has led to more measurement of electrostriction of polymers. Many kinds of polymers including poly(vinylidene fluoride), poly(vinyl chloride), poly(methyl methacrylate) were studied by other researchers. Large electrostriction of thermal plastic elastomers and highly plasticized poly(vinylidene fluoride) were reported.;One of the objectives of this dissertation was to study electrostriction of some commercial rubbers. The rubbers polychloroprene, polyisoprene, nitrile, chlorobutyl, and chlorosulfonated polyethylene were formulated and cured in a way ordinarily used for rubber applications. The electrostriction was measured in the direction of electric field. A large electrostrictive coefficient was observed for the polychloroprene rubber, which is in the order of magnitude of 10;The other objective of this dissertation was to develop a theoretical model of electrostriction of rubbers which relates electrostriction to their dielectric and elastic properties. A model was developed based on the reorientation of chain segments induced by the alignment of dipole moments in the direction of electric field. After further refinement, it can be used to predict the electrostrictive behavior of a certain elastomer based on their chemical structures and lead to discovery of polymers of large electrostrictive effects. |
