Patent ID: 8252887

Claim:
A copolymer comprising a first repeating unit having the structure: and a second repeating unit having the structure: wherein X 1 , X 2 , X 4 and X 5 , are independently selected from the group consisting of O, S and NR 3 , wherein R 3 is selected from the group consisting of hydrogen and alkyl groups containing from one to six carbon atoms; Ar 1 is selected from the group consisting of phenylene, optionally substituted with from one to four substituents independently selected from the group consisting of halogen, halomethyl, halomethoxy, methyl, methoxy, thiomethyl, nitro, sulfoxide and sulfonyl; R 1 is selected from the group consisting of optionally substituted alkylene, heteroalkylene, alkenylene and heteroalkenylene groups containing from one to ten carbon atoms; and B is selected from the group consisting of optionally substituted alkylene groups of 1 to 18 carbon atoms, optionally substituted heteroalkylene groups of 1 to 18 carbon atoms, optionally substituted alkenylene groups of 1 to 18 carbon atoms and optionally substituted heteroalkenylene groups of 1 to 18 carbon atoms.