The blending between poly(methyl methacrylate) (PMMA) and ferroelectric (vinylidene fluoride-trifluorethylene) [P(VDF-TrFE)] copolymer chains has been investigated by Fourier transform infrared (FTIR) spectroscopy over the full range of composition, for the copolymer with 50 mol % of trifluorethylen
Dielectric behavior of P(VDF-TrFE)/PMMA blends
โ Scribed by L. O. Faria; R. L. Moreira
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 193 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0887-6266
No coin nor oath required. For personal study only.
โฆ Synopsis
Binary blends of ferroelectric (vinylidene fluoride-trifluorethylene) copolymer [P(VDF-TrFE)] and amorphous poly(methyl-methacrylate) (PMMA) were investigated over the full range of composition, for the copolymer with 50 mol % of trifluorethylene. Dielectric measurements confirmed that the system becomes amorphous when the PMMA contents exceed 40 wt %. The observed dielectric losses could be attributed to the ferroelectric transition of the copolymer and to molecular relaxations, characteristic of the individual polymers. We demonstrate the thermally activated nature of the โค-PMMA and โค-P(VDF-TrFE) relaxations, with activation energies of 29.3 and 13.5 kcal/mol, respectively. We also demonstrate that the โค-P(VDF-TrFE) relaxation cannot be attributed only to the copolymer glass transition and that its origin is not in the crystalline region, based on experimental evidences.
๐ SIMILAR VOLUMES
Structural changes in poly(vinylidene fluoride)-trifluoroethylene [P( VDF-TrFE)] copolymers caused by X-ray irradiation were investigated by molecular weight determination, EPR analysis, FTIR spectroscopy, gel content, DSC thermal analysis, Xray diffraction, and piezoelectricity measurements. Sample
A systematic study was carried out on the effect of the crystallization temperature (T cr ), on the phase transitions presented by P(VDF/TrFE) copolymers cast from dimethylformamide (DMF) solution with molar ratios 60/40, 70/30, and 80/20. The results obtained by differential scanning calorimetry (D