NBN ISO 21561-2:2021

Styrene-butadiene rubber (SBR) — Determination of the microstructure of solution-polymerized SBR — Part 2: FTIR with ATR method ((ISO 21561-2:2016))


About this standard

Publication date
29 May 2021
ICS Code
83.060 (Rubber)

About this training


This part of ISO 21561 specifies procedures for the quantitative determination of the microstructure
of the butadiene and the content of styrene in solution-polymerized SBR (S-SBR) by Fourier Transform
Infrared Spectrometry (FTIR) with Attenuated Total Reflection (ATR) method. The styrene content is
expressed in mass % relative to the whole polymer. The vinyl, trans and cis contents are expressed in
mol % relative to the butadiene content. This method is only applicable to raw rubbers.
NOTE 1 Precision as shown in Annex A may not be obtained for S-SBRs containing polystyrene block or
styrene content more than 45 mass %.
NOTE 2 Only “vinyl”, “trans” and “cis”, are used in this part of ISO 21561. However, the expression of vinyl,
trans and cis mean as follows in general:
— vinyl: vinyl unit, vinyl bond, 1,2-unit, 1,2-bond, 1,2-vinyl-unit or 1,2-vinyl-bond;
— trans: 1,4-trans unit, 1,4-trans bond, trans-1,4 unit or trans1,4 bond;
— cis: 1,4-cis unit, 1,4-cis bond, cis-1,4 unit or cis-1,4 bond.