Perfluorinated Polydioxolane Derivatives

The recent studies of partially halogenated polymers described in the previous sections were undertaken to obtain GI POFs with sufficiently low attenuation at specific light source wavelengths at a relatively low cost. These polymers can be categorized as intermediate materials between PMMA and CYTOP on the basis of their performance and material cost, both of which meet the current demand. 

The polymers are purified by precipitation from their solutions in hexafluoroben-zene in chloroform. 

The molecular weight of the polymers can be controlled by the concentrations of the free-radical initiator and/or chain-transfer agents such as carbon tetrabromide. Typical results of the preparation of poly(perfluoro-2-methylene-4-methyl-l,3-dioxolane) using different concentrations of the initiator and chain-transfer agent are reported in [27]. 

The most remarkable observation in the series of dioxolane polymers is that some derivatives with relatively bulky substituents show excellent values of up to 185 °C. Considering that the operating temperature of CYTOP-based GI POFs 

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