Dielectric And Electric Field Induced Strain Of Modified Acrylic Resin Elastomer

Electroactive polymers (EAPs) that respond to external electrical stimulation with a huge size orshape change are an emerging kind of functional material. EAPs have special electromechanicalproperties since they can convert electrical energy to movement and mechanical energy underelectrical field. The critical factors that affect the electromechanical properties of EAPs are elasticmodulus and dielectric constant. To improve the dielectric constant of the polymer while keep itssoftness was the aim of this research.Copper phthalocyanine oligomer (CuPc) was synthesized by wet-process and the acrylic elastomer(AE) was synthesized using solution free radical copolymerization method. CuPc was chemicallygrafted to the backbone of AE to fabricate all-organic nanocomposites. The FT-IR and1H NMRproved that CuPc was grafted to AE successfully. According to TEM photographs, the size of CuPcparticles dispersed in AE/CuPc was about400nm, approximately8times of that in AE-g-CuPc inwhich the size of CuPc particles was40~50nm. Cross-sectional SEM photographs showed thatcompared with the solution-cast film which had a polymer layer, hot-press films had more uniformmorphology. DSC and TG analysis showed that the thermal stability of the composites was higherthan pure AE. The dielectric constant and dielectric loss of the composites increased with the increaseof CuPc. The dielectric constant of AE-g-15wt%CuPc was up to233at100Hz under roomtemperature,54times of that of pure AE and1.5times of that of AE/15wt%CuPc. The dielectricconstant of the hot-press film of AE-g-15wt%CuPc can reach as high as385at100Hz,1.6times ofthat of AE-g-15wt%CuPc prepared with solution-cast method. What’s more, even at high frequencies,the dielectric constant of the hot-press film was still relatively high. The dielectric loss of hot-pressfilms was less than that of solution-cast films. The enhancement of dielectric response of thecomposites can be attributed to the interface exchange coupling effect, as well as theMaxwell-Wagner-Sillars (MWS) polarization mechanism.According to the analysis of electric field induced strain, the in-plane strain of AE-g-5wt%CuPcmembrane was3.4%under an electric field of13.2V/μm, the in-plane strain of AE-g-15wt%CuPcwas9.6%under12.2V/μm.