Polyamide 11/Poly(vinylidene fluoride) Blends as Novel Flexible Materials for Capacitors
writer：Rui Li, Chuanxi Xiong, Dongliang Kuang, Lijie Dong, Youan Lei, Junlong Yao
keywords：dielectric properties, electrical properties, flexible, intermolecular interactions, PA11/PVDF blends, SMA
source：期刊
Issue time：2008年
A novel capacitor with high dielectric constant (e) has been developed by blending poly-(vinylidene fluoride) (PVDF) with polyamide (PA11). The blends show high dielectric constants (eblend¼40), which give better frequency stability (1 MHz), and excellent mechanical properties. Based on certain volume fractions, the measured dielectric constants (eblend) were found to exceed those of the corresponding polymers, in contrasted to conventional composites, where εpolymerA<εcomposite<εpolymerB. SEM investigations suggest that the enhanced dielectric behavior originates from significant interfacial polymer-polymer interactions. DSC and XRD demonstrate that blending PA11 with PVDF affects the crystalline behavior of each component. However, the PA11/PVDF blends exhibit a slightly high dielectric loss (tand0.17), which is a great disadvantage to a capacitor. Adding a copolymer of styrene and maleic anhydride decreased the dielectric loss (tand0.057) and increased the dielectric constant (eblend¼60). Our findings suggest that the high-e polymeric blends created represent a novel type of material that is flexible and easy to process, of relatively high dielectric constant, of high breakdown strength and, moreover, is suited to applications in flexible electronics.