Perfluoro-4-methyl- 1,3-dioxolane

These perfluoropolymers have excellent properties in many aspects. However, the preparative methods are complex and expensive and of Cytop is relatively low. Several substituted perfluoro-2-methylene-l,3-dioxolanes (Figure 16.5) have been studied to obtain other perfluorinated polymers. The first example in the class is perfluoro-2-methylene-4-methyl-l,3-dioxolane (Figure 16.5B), which was prepared by DuPont in 1967 through perfluoropyruvyl fluoride prepared from hexafluoro-propylene oxide [7]. Using a similar method, perfluoro-2-methylene-4,5-dimethyl-1,3-dioxolane (Figure 16.5D) was synthesized by Asahi Glass in 1993 [12]. 

TABLE 163 Effect of the Concentration of Initiator on the Properties of Poly(perfluoro-2-Methylene-4-Methyl-13-Dioxolane) Prepared in Bulk"... 

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]. 

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