Additionally, other polymers and copolymers such as polyethylene 2,6 naphthalate, a copolymer based on 1,4-cyclohexanedimethylene terephthalate (PCTG), and copolymers of gluterimide and methyl methacrylate (KAMAX resins, available from Rohm and Haas), are useful in the practice of the present invention.