Hexafluoropropylene INDEX

Figure 14-2. The relationship between the refractive index d for the sodium D line (589.3 nm) and the Abbe dispersion v for various polymers [see Equation (14-12)]. PVCz, poly(A-vinyl carbazole) P(TFE-HFP), copolymer of tetrafluoroethylene and hexafluoropropylene. For other abbreviations, see Table VII-6, Appendix.

First Polymer Series. The first series of polymers was investigated, in order to limit the interaction between an AFM probe and polymer surfaces to only the dispersion (London) component of the Van der Waals force. Adhesional forces were measured between a S10,t probe and a set of nonpolar polymers that provided a range of refractive indexes (as measured) polystyrene (1.582), isotactic polypropylene (1.501), poly(vinylidene fluoride) (1.407), and poly(tetrafluoroethylene-co-hexafluoropropylene) (1.348). The histograms of the pull-off forces, measured with a SiOx probe, are shown in Figure 2 and tabulated with the calculated values for adhesion energy in Table 1. 

Specific IR ratio, also known as HFPI (HFP Index), is defined as the ratio of net infrared absorbence at 10.18 and 4.25 microns of a film of the copol Tner (50 pm) made by melting a sample of the resin in a press followed by water quenching. Couture, et at, reported that by multiplying the Specific IR ratio by 4.5, weight percent of the hexafluoropropylene in the copolymer can be obtained. 

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