Cytop stability

All three commercial amorphous fluoropolymers. Teflon AF, Hyflon AD, and Cytop posses a unique set of properties. All dissolve in fluorinated solvents and thus may be spin coated to produce thin hlms and coatings. The polymers may also be extruded and molded using traditional polymer processing techniques. Note that the polymers are not soluble in hydrocarbon solvents or water and retain the chemical and thermal stability of perfluorinated polymers such as Teflon . These polymers have lower density than the well-known semicrystalline perfluorinated polymers such as pTFE that results in lower refractive index, lower thermal conductivity, higher gas permeability, and lower dielectric constant. The polymers are transparent and have excellent mechanical properties below their Tg due to their amorphous character. The presence of a heterocyclic ring in the polymer backbone of these materials is key... 

From this analysis the stability of Cytop in oxygen is estimated to be about 20 days at 250 °C and 417 days at 220 °C. In addition, the thermal stability of Cytop in nitrogen was determined in a similar manner and the time to the onset of decomposition at 250 °C was shifted by more than an order of magnitude beyond the value found for degradation in oxygen. Actual extrusion trials of this material in the melt indicate these predicted lifetimes are reasonable estimates of Cytop s stability. 

Besides, high-performance polymer electrets, sueh as Parylene HT and certain types of CYTOP, were introduced to the family of electret materials. They exhibit not only excellent electret properties (high surfaee charge density with exceptional long-term and thermal stability) but also good compatibility with MEMS fabrication process. 

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