Kopolymer kyseliny 4-(1,1-dimethylethyl)benzoové, ftalanhydridu a 2-methyl-2-hydroxymethyl-1,3-propandiolu
4-(1,1-dimethylethyl)benzoic acid, polymer with 1,2-benzenedicarboxylic anhydride and 2-methyl-2-hydroxymethyl-1,3-propanediol