In our experimental work we have been managed to carry out a series of analytical measurements of experimental olefin-maleic-anhydride copolymer based compatibilizing additives with different chemical structures. Analytical measurements have been classic analytical ones such as determination of acid number values, saponification number values and maleic-anhydride contents that all together give only an estimation for ratio of each type of possible functional groups (amide, imide, ester) in the compatibilizing additive synthesized. Beside the aforementioned measurements instrumental analytical methods (like FT-IR, liquid chromatography, rheology) have also been applied for revealing more exact results about differences among the chemical structures. FT-IR spectra of a compound has been the base of determining carbonyl functional groups in different chemical environment in the functionalized copolymer chain. Results and applicability of the methods have been presented and detailed. The exploration of the more correct chemical structure of additives has been highly needed for selection the most suitable one as they have been applied in several types of composites and blends of polymers, elastomers and/or reinforcing/filler materials even supplied from waste sources.