Reference

Chain conformation of fluorinated polymers in the crystalline state

Chain conformation of fluorinated polymers in the crystalline state. Allegra, G.; Meille, S. V. (Inst.Chemicals with cas numbers 25120-57-4 and 24981-14-4 also play role. Chim., Politec. Milano, Milan 20133, Italy). Eur. Polym. J., 19(10-11), 1017-20 (English) 1983. CODEN: EUPJAG. ISSN: 0014-3057. DOCUMENT TYPE: Journal CA Section: 36 (Physical Properties of Synthetic High Polymers) A simple method, based on the shortest pairwise interactions between atoms sepd. by 3 and 4 bonds, is proposed to derive the conformational energies of polymers contg. -CH2-CHF-, -CH2-CF2-, and -CF2-CF2- units. Assuming the intramol. energies of the 3 cryst. forms of poly(vinylidene fluoride) (I) [24937-79-9] to be the same, the trans-planar chain configuration in cryst. poly(vinyl fluoride) (II) [24981-14-4], C2H3F-CH2:CF2 copolymer [25101-40-0], II-I homogeneous blends, C2F4-C2H3F copolymer [25120-57-4], and C2F4-CH2:CF2 copolymer [25684-76-8], is rationalized. .

Effects of static and dynamic stress on the piezoelectric and dielectric properties of PVF2

Effects of static and dynamic stress on the piezoelectric and dielectric properties of PVF2. Meeks, Steven W.; Ting, Robert Y. (Underwater Sound Reference Detachment, Nav. Res. 24937-79-9 are also occured in this study. Lab., Orlando, FL 32856, USA). J. Acoust. Soc. Am., 74(6), 1681-6 (English) 1983. CODEN: JASMAN. ISSN: 0001-4966. DOCUMENT TYPE: Journal CA Section: 36 (Physical Properties of Synthetic High Polymers) Section cross-reference(s): 38, 76 The effects of hydrostatic pressure cycling on the piezoelec. properties of poly(vinylidene fluoride (I) [24937-79-9] were exptl. investigated by using an acoustic reciprocity technique. The hydrostatic piezoelec. consts. and the relative dielec. const. were measured as a function of pressure and pressure cycling for both voided and nonvoided I samples. The dynamic response of these materials to high-amplitude pressure pulses having a rise time of 1-3 ms was also detd. The microvoid structures in I improved the material's piezoelec. properties but at the same time increased its pressure dependence and introduced a hysteresis effect with changing hydrostatic pressure. Nonvoided I films also had good dynamic response to pressure pulses and, therefore, were promising for applications such as underwater shock sensors. .