SYNTHESIS OF HETEROCYCLIC POLY(PHTHALAZINONE ETHER NITRILE) FLUORIDE POLYSILOXANE BLOCK COPOLYMERS AND THEIR HYDROPHOBIC THIN FILMS: SYNTHESIS OF HETEROCYCLIC POLY(PHTHALAZINONE ETHER NITRILE) FLUORIDE POLYSILOXANE BLOCK COPOLYMERS AND THEIR HYDROPHOBIC THIN FILMS