ISO 21561-1:2015规定了用1H-NMR光谱法（绝对法）和红外光谱法（相对法）定量测定溶液聚合丁苯橡胶（S-SBR）中丁二烯微观结构和苯乙烯含量的程序。苯乙烯含量以相对于整个聚合物的质量百分比表示。反式、顺式和乙烯基含量以相对于丁二烯的摩尔%表示。这些方法仅适用于生橡胶。 注1:通过1H-NMR光谱法获得的已知绝对微观结构的S-SBR校准，IR光谱法也可以给出微观结构的绝对值。 注2:ISO 21561本部分仅使用“乙烯基”、“反式”和“顺式”。然而，乙烯基、反式和顺式的表达通常如下所示: -乙烯基:乙烯基单元、乙烯基键、1,2-单元、1,2-键、1,2-乙烯基单元或1,2-乙烯基键； -反式:1,4-反式单元、1,4-反式键、反式1,4单元或反式1,4键； -顺式:1,4-顺式单元、1,4-顺式键、顺式1,4单元或顺式1,4键。

ISO 21561-1:2015 specifies procedures for the quantitative determination of the microstructure of the butadiene and the content of styrene in solution-polymerized SBR (S-SBR) by 1H-NMR spectrometry as an absolute method and by IR spectrometry as a relative method. The styrene content is expressed in mass % relative to the whole polymer. The trans, cis and vinyl contents are expressed in mol % relative to the butadiene. These methods are applicable only for raw rubber. NOTE 1 IR spectrometry can also give absolute values of microstructure by calibration with S-SBRs of known absolute microstructure obtained by 1H-NMR spectrometry. 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.