"polyalkylmethacrylates wherein alkyl has from 3 to about 18 carbon atoms, including propyl, butyl, hexadecyl, and the like, including poly(n-propyl methacrylate), such as #828, available from Scientific Polymer Products, poly(n-butyl methacrylate), such as #213, available from Scientific Polymer Products, poly(n-butyl methacrylate-coisobutylmethacrylate), such as #209, available from Scientific Po" . . . .