Effects of hydrolysis degree on the formation of ferroelectric-core fillers and the electric performance of polyvinyl alcohol composites

Abstract

Dielectric materials have been regarded as an emerging field for dielectric energy storage in the last few decades. To improve the dispersion of high-dielectric-constant fillers in polymer, many methods of surface modification and core-shell structure have been reported focusing on the forming of shell. Here we introduce a soluble ferroelectric [Hdabco]ClO4 (TEDA.C, dabco = diazabicyclo[2.2.2]octane) into polyvinyl alcohol (PVA) matrix via solution mixing to create a ferroelectric TEDA.C crystal core by the hydrogen bonding between PVA and TDEA.C. We studied the effects of PVA's chain structure on the interfacial interactions between the two components, the crystalline phase of TEDA.C, and the dielectric, ferroelectric, and physical properties of composites by employing three PVAs of different hydrolysis degree. High hydrolysis degree promoted the homogeneous distribution and fine miscibility of TEDA.C in PVA matrix, but also impeded the hydrogen bond movement of TEDA.C, which resulted in the disordered paraelectric phase of ordered-disordered-type ferroelectric. Comparing the dielectric, ferroelectric and physical properties of three PVA systems provides further insights about the hydrolysis degree of PVA benefitting the interfacial interaction and interfacial effects, leading to a potential facile and powerful tool for tuning the properties of PVA composites.