초록 |
Block copolymers containing polydimethylsiloxane (PDMS) as soft segments have had a unique property. We synthesized siloxane-urethane copolymers for the application of actuators. Polyurethanes known as electrostrictive material have had rapid response time of electric field induced strain, but the amount of displacement is small. To improve this problem, we introduced PDMS as soft segments, which has an extremely low glass transition temperature (-123℃), then its mechanical properties sustain even at very low temperature. High molecular weight siloxane-urethane copolymers were synthesized by conventional prepolymer method and obtained in the form of films by casting method. Electric field induced strains of siloxane-urethane copolymers were measured. When voltage is applied to the electrodes, the elastomeric films expand in area and compress in thickness. The dielectric constant, displacement and recovery time were also measured. |