Polyvinylene fluoride

Remarkably some polymers are ferroelectric. Polyvinylene fluoride, as a thin film (approximately 25 /mi thick) is used in Shockwave experiments to measure stress. The pressure range over which this polymer operates is an order of magnitude larger than that of quartz or lithium niobate. 

In the P phase of polyvinylene fluoride (PVDF), the CF2 groups in a polymer chain are all pointing in the same direction (Figure 9.20), so that a dipole moment... 

The simplest systems to start with are the high m.wt. homopolymers of the fluoroethylenes for which complications due to branching, end groups, etc., are minimal. In this section, we therefore outline the results from studies on polyethylene (high density), polyvinyl fluoride, polyvinylidene fluoride, polyvinylene fluoride, polytrifluoroethylene and polytetrafluoroethylene. 

The Cis spectrum of polyvinyl fluoride shows two partially resolved peaks of equal area corresponding to HF and 1CH2 carbons whilst for polyvinylene fluoride in addition to the main peak corresponding to HF carbons and hydrocarbon calibration peak, there... 

Absolute binding energies calculated for model systems of polyethylene, polyvinylene fluoride and PTFE. 

Fig. 5 shows experimental charge distributions determined for polyvinylene fluoride and polytrifluoroethylene. These show rather effectively the large net migration of electron densities from carbon and hydrogen to fluorine. 

Fig. 5. Experimental charge distributions for polyvinylene fluoride and polytrifluoroethylene.

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