Does the copolymer poly(vinylidene cyanide-tricyanoethylene) possess piezoelectricity?
The geometry, energy, internal rotation barrier, dipole moment, and molecular polarizability of the α- and β-chain models of poly(vinylidene cyanide-tricyanoethylene) [P(VDCN-TrCN)] were studied with density functional theory at the B3PW91/6-31G(d) level. The effects of the chain length and the TrCN content on the copolymer chain stability, the chain conformation, and the electrical properties of P(VDCN-TrCN) were examined and compared with those of poly(vinylidene fluoride-trifluoroethylene) and PVDCN to gauge whether P(VDCN-TrCN) would be expected to possess substantial piezoelectricity. The results of this study showed that the stability of the β conformation increases and the energy difference per monomer unit between the β- and α-chains decreases with increasing TrCN. However, introducing TrCN into VDCN will not significantly enhance the radius of curvature of the P(VDCN-TrCN) chains. The average dipole moment per monomer unit in the β-chain is affected by the chain curvature and the TrCN content. The amount of piezoelectricity present in P(VDCN-TrCN) is slightly smaller than that in PVDCN, and is less than that in poly(vinylidene fluoride-trifluoroethylene).
School of Chemical and Environmental Sciences, Shaanxi University of Technology, Hanzhong, Shaanxi 723001, People's Republic of China. wangzy525@yahoo.com.cn
Zhi-Yin
ZY
Wang
Ke-He
KH
Su
Qiong
Q
Xu
D019281:Dimerization; D004560:Electricity; D011145:Polyvinyls / Q000737:chemistry*; D013816:Thermodynamics
D011145:Polyvinyls