Polyimide-Teflon composites

Figure 4. Dielectric properties for polyimide-Teflon composites.

Figure 5. Water absorption vs. wt % Teflon for PMDA/ODA polyimide-Teflon composites.

Laminates have been extensively studied by PA-FTIR and are the subject of extensive investigations by the new much more complex step-scan PA-FTIR techniques. Kapton film is often used to illustrate the analysis of this type of sample. Kapton 200FN919 film is a DuPont product which consists of a 25 pm layer of polyimide laminated between 12.7 pm layers of Teflon. If a high mirror velocity is used then a spectrum of only the Teflon layer is obtained. On the other hand if a slow mirror velocity is used a composite spectrum of the Teflon and polyimide layer is obtained. The difference spectrum (low mirror velocity spectrum minus high mirror velocity spectrum) represents that of the polyimide layer. As illustrated in Figure 2.16 the difference spectrum closely resembles the PA FTIR spectrum of polyimide except for the regions where the strong C-F bands of the Teflon are present. 

Automotive and electrical/electronics industries are the largest markets for engineering polymers which include Crastin PBT polyesters, Hytrel thermoplastic polyester elastomers, Rynite PET, high-temperature Thermx PCT (polycyclohexylene dimethyl terephthalate), Tribon composites and Tynex filaments, Vespel polyimide parts and shapes, Zenite liquid crystal polymers and Zytel PA resins. In July 2005, DuPont launched the DuPont Vespel SP-202 composition whose properties include the prevention of static charge build-up. Other products include Delrin acetal resins, engineering thermoplastic vulcanisates. Minion mineral reinforced PA resins and Teflon PTFE fluoropolymer resins. 

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