Patent ID: 8889043

Claim:
A method for casting a styrenic fluoropolymer film on a substrate comprising the steps of: preparing a polymer solution by dissolving the fluoropolymer in a solvent or solvent blend whose Hansen solubility parameters (HSPs, MPa 1/2 ) satisfy the following relations: |SP b −SP p |<5, |SP b −SP s |<4, |SP b(H) −SP p(H) |<7, and 2<|SP b(H) −SP s(H) |<10, wherein SP b , SP p , SP s are the total Hansen solubility parameters of solvent/solvent blend, fluoropolymer, and substrate, respectively; SP b(H) , SP p(H) , and, SP s(H) are the hydrogen-bond Hansen solubility parameters of solvent/solvent blend, fluoropolymer, and substrate, respectively; wherein the fluoropolymer comprises a moiety of: wherein R 1 , R 2 , and R 3 are each independently hydrogen atoms, alkyl groups, substituted alkyl groups, or halogens, wherein at least one of R 1 , R 2 , and R 3 is a fluorine atom, and wherein R is each independently a substituent on the styrenic ring, n is an integer from 0 to 5 representing the number of the substituents on the styrenic ring; and casting the polymer solution on a substrate.