This Is AuburnElectronic Theses and Dissertations

Fabrication and Characterization of Blends of P(VDF-CTFE) 91/9 and PMMA

Date

2019-04-16

Author

Shen, Jialiang

Type of Degree

Master's Thesis

Department

Materials Engineering

Abstract

Transparent and flexible polymer blends with a uniform thickness of films about 8 microns were successfully and simply fabricated by a spin-coating method. PMMA polymer and P(VDF-CTFE) 91/9 mol. % (VC91) copolymer were mixed and dissolved in DMF solvent, with different volume fraction of PMMA from 0 vol. % to 100 vol. %. Dielectric properties, polarization-electric field (P-E) hysteresis loops and differential scanning calorimetry (DSC) were measured in this study. At room temperature, dielectric constant decreased, while dielectric loss decreased at low frequency and increased at high frequency, with increasing volume fraction of PMMA. Temperature dependence of dielectric properties were investigated and explained by several relaxation processes. With increasing PMMA content, breakdown fields increased, and maximal polarization and remnant polarization decreased. Energy-storage performances were calculated from P-E loops. Maximum charged and discharged energy density were about 26.4 J/cm3 and 10.4 J/cm3, obtaining in PMMA-VC91 blends with 10 vol. % and 30 vol. % of PMMA, respectively. Also, efficiency increased as the addition of PMMA. The phase transitions, such as glass transition, fusion, crystallization, were investigated by DSC, assisting to understand the dielectric behaviors of PMMA-VC91 blends.