Scope:

The ASTM D5594 test method covers the determination of the vinyl acetate content of ethylene-vinyl acetate (EVA) copolymers by Fourier Transform Infrared Spectroscopy (FT-IR). This test method applies to the analysis of EVA copolymers containing 0.5 to 55% vinyl acetate. The amount of vinyl acetate included in EVA copolymers possesses an effect on its properties therefore the level of vinyl acetate in copolymer samples is determined using this ASTM D5594 test method.

Procedure:

For the ASTM D5594 test the vinyl acetate content is first obtained by measuring the infrared absorption band at 1020 cm^-1(0.5 to 5% vinyl acetate) or 609 cm^-1(5 to 55% vinyl acetate).  Then, internally, the sample thickness is obtained using an ethylene infrared absorption band at  720 cm^-1(28 to 55% vinyl acetate), 2020 cm^-1(0.5 to 28% vinyl acetate), or 4250 cm^-1(5 to 28%  vinyl acetate). For EVA copolymer standards, regression analysis is performed on vinyl acetate/ethylene ratios versus known vinyl acetate concentrations. The vinyl acetate content of successive EVA copolymer samples is calculated using the resulting equation.

Specimen size:

For the ASTM D5594 test procedure, pressed films and molded plaques are used as test specimens.

Data:

The percent vinyl acetate is reported in SI units and is considered standard.

Conclusion:

The ASTM D5594 test method covers the determination of the vinyl acetate content of ethylene-vinyl acetate (EVA) copolymers by Fourier Transform Infrared Spectroscopy (FT-IR).