Fluoropolymers bond values

Electrooptical properties will be covered only briefly. Fluorocarbons find widespread utility in altering electrooptical properties of coatings. These properties are to be considered as derived from bulk properties of the fluorocarbon. In that regard, fluoropolymers are the most often selected. It is known from Eq. (2) that the electrooptical properties of fluorocarbons can be linked directly to the nature of the C—F bond (a oc n and e <=< n ). It is instructive to consider some relevant values. The dielectric constants e of PTFE, PE, and nylon-6,6 have been determined to be 2.1 (60 Hz-2 GHz), 2.2-2.3 (1 kHz), and 3.6-3.0 (100 Hz-1 GHz), respectively. The dielectric constants for PE and PTFE are comparable. The explanation can be found by comparing segmental polarizabilities a for groups with C—F bonds versus those with C—H bonds, as shown in Table 4.1. They are nearly identical. As e is related to a, it is not surprising that PE and PTFE have similar dielectric constants. The value of e for nylon-6,6 is included above for comparison. 

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