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
Effect of X-ray radiation on the structure of P (VDF/TrFE) copolymers
β Scribed by H. N. da Cunha; L. H. C. Mattoso; R. M. Faria
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 130 KB
- Volume
- 35
- Category
- Article
- ISSN
- 0887-6266
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β¦ Synopsis
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. Samples exhibit radiation-induced conductivity (RIC) due to the formation of radical ions. These radicals are generated by bond cleavage, which could react, leading to structural changes such as oxidation, double bond formation, chain scission, and crosslinking. The increasing gel content with radiation dose indicated that crosslinkings of the polymer chains predominate. Irradiation on P(VDF-TrFE) caused the melting temperature, heat of fusion, and Curie temperature to decrease. These results are consistent with the partial destruction of crystalline domains.
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