ASTM D2702-05(2021)

5.1This procedure can be used for a variety of applications, including identifying unlabeled material, process control, raw material acceptance, product evaluation, and compositional change during environmental testing.

5.2Rubber chemicals vary widely in their chemical and physical properties. Infrared spectrophotometers vary in the presentation of a spectrum (some are linear with absorbance, others with transmittance, some use grating for energy dispersion, others use a sodium chloride prism, some obtain a spectrum through a mathematical Fourier Transform, and the like). For these reasons, a single universal method of specimen preparation and set of instrument parameters is not possible.

5.3By using a specific sampling procedure and operating conditions, a given spectrophotometer will give an absorption curve that is characteristic of the rubber chemical or mixture under investigation.

5.4The ability to superimpose the infrared spectrum of the test specimen upon that of a reference specimen, obtained under the same conditions, is evidence that the two are identical.

5.5The presence of additional absorption bands in either the test specimen or the reference specimen indicates the presence of one or more additional components.

1.1This practice covers a simple, rapid practice to prove the identity of a rubber chemical before incorporation into a rubber mix by comparison of its infrared absorption spectrum with that of a reference specimen.

1.2This technique can also be used to detect gross contamination or large differences in rubber chemicals. Thus, it can provide a basis for producer-consumer agreement.

1.3Wherever infrared spectrophotometer is used, Fourier Transform Infrared Spectrometer (FTIR) may also be understood.

1.4This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.