Effect of annealing on the structure of oriented polyvinyllidenfluoride

Kosmynin, B.P.; Gal'perin, Ye.L.; Tsvankin, D.Ya.

doi:10.1016/0032-3950(72)90133-5

Cited by 6 publications

(1 citation statement)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…the β phase has piezo- and pyroelectric properties . The correlation of crystalline structure and resultant electrical properties has led to several studies in which it was attempted to prepare different phases by altering thermal history, mechanical deformation, γ irradiation, or pressure . In addition, PVDF shows low acoustic impedance .…”

Section: Introductionmentioning

confidence: 99%

Influence of Polymer End Groups on Crystallization and Morphology of Poly(vinylidene fluoride) Synthesized in Homogeneous Phase with Supercritical Carbon Dioxide

2008

View full text Add to dashboard Cite

Poly(vinylidene fluoride) (PVDF) samples from homogeneous phase polymerizations in supercritical CO2 and subsequent expansion to ambient conditions were analyzed with respect to polymer end groups, crystallinity, type of polymorphs, and morphology. Upon expansion the polymer was obtained as white particles. Scanning electron microscopy showed that DTBP (di-tert-butyl peroxide) derived polymer end groups lead to stack-type particles whereas sponge- or rose-type particles were obtained in case of chain transfer agent fragments as end groups. FTIR (Fourier-transform infrared spectroscopy) and WAXD (wide-angle X-ray diffraction) indicated that the type of polymorph, α or β crystal phase, is significantly affected by the type of end group. In addition, the crystallinity of the material, as determined via differential scanning calorimetry, is affected by the end groups and polymer molecular weights. For example, with M n around 6700 g·mol−1 crystallinity ranges from 29% for DTBP-derived endgroups to a maximum of 64% for end groups originating from perfluorinated hexyl iodide used as chain transfer agent during polymerization.

show abstract