Characterization and properties of semicrystalline and amorphous perfluoropolymer: Poly(perfluoro-2-methylene-1,3-dioxolane)

The low and the high molecular weight poly(perfluoro-2-methylene-1,3-dioxolane)s were prepared using perfluorobenzoyl peroxide as a free radical initiator. Both polymers obtained were semicrystalline and insoluble in organic solvents. The glass transition temperatures (T_g) of polymers obtained were 94-106°C, and their melting points were 224-229°C. Wide-angle X-ray diffraction measurements showed that polymers as prepared are semi-crystalline (21% crystalline fraction) and the crystallinity increased to 47% after annealing at 170°C. However, the films prepared by heating (at 230-250°C) and pressing of the high molecular weight polymers are transparent and flexible. The refractive index of the film is 1.3320 and 1.3245 at 533 and 1546nm, respectively. The transparent polymer films did not recrystallize while annealing below T_g, and they are chemically and thermally stable. This polymer may have potential applications in optoelectronic fields.