Styrene-butadiene rubber (SBR) is a major source material for the fabrication of elastomer products. Depending on its origin, differences are observed between SBR samples by tabletop NMR spectroscopy that relate to the constitution of the macromolecular chains. This study reports experimental results from the analysis of 108 SBR samples by low-field ¹H and ¹³C NMR spectroscopy at 1 T in combination with partial least square regression to develop methodology for quality control of raw rubber. The partial least square regression (PLS-R) models were developed for quantifying the individual monomer units present in the SBR which are impossible to quantify because of peak overlap in the SBR ¹H NMR spectrum obtained at 1 T. The spectra revealed differences between samples from the same and different manufacturing batches of same and different manufacturers from different countries in a qualitative and quantitative fashion. The range of samples included regular and oil-extended solution and emulsion polymerized SBR. Referring to high-field spectra acquired 9.4 T the peaks in the low-field ¹³C NMR spectra could be assigned for determining the rubber microstructure, and the content of different repeat units could be quantified by partial least squares regression. Over 12 repeatable measurements the standard deviation in mass % was 0.03%, 0.06%, 0.05%, 0.33% and 0.37% for the contents of styrene, 1,2-butadiene, 1,4-butadiene, trans-1,4-butadiene and cis-1,4-butadiene units, respectively. Among the 7 different sampling points in a delivery, the standard deviation was 0.51% for 1,2-butadiene, 0.88% for styrene, 0.56% for 1,4-butadiene unit, 0.31% for trans-1,4-butadiene and 0.68% for cis-1,4-butadiene units. The root-mean-square error of prediction (RMSEP) for styrene, 1,2-butadiene, 1,4-butadiene, and trans-1,4-butadiene was 0.15, 0.29, 0.29, and 0.28 with R² values of 0.93, 0.92, 0.92, and 0.95, respectively, demonstrating the potential of low-field NMR spectroscopy with compact instruments for quality control of raw rubber when used in combination with effective analytical procedures such as chemometrics.

苯乙烯-丁二烯橡胶（SBR）是制造弹性体产品的主要原料。根据其来源，通过台式NMR光谱在SBR样品之间观察到差异，这与大分子链的构成有关。这项研究报告了通过1 T的低场¹ H和¹³ C NMR光谱结合偏最小二乘回归分析108种SBR样品的实验结果，从而开发了生胶质量控制方法。开发了偏最小二乘回归（PLS-R）模型用于量化SBR中存在的单个单体单元，这些单体单元由于SBR ^1中的峰重叠而无法量化在1 T下获得的1 H NMR光谱。该光谱以定性和定量的方式揭示了来自不同国家的相同制造商和不同制造商的不同制造批次的样品之间的差异。样品范围包括常规和充油溶液以及乳液聚合的SBR。参照获得的9.4 T高场光谱，可以指定低场¹³ C NMR光谱中的峰以确定橡胶的微观结构，并且可以通过偏最小二乘回归来量化不同重复单元的含量。在12个可重复测量中，苯乙烯，1,2-丁二烯，1,4-丁二烯，反式-1,4-丁二烯的含量的质量％标准偏差为0.03％，0.06％，0.05％，0.33％和0.37％与顺-1,4-丁二烯单元。在交货的7个不同采样点中，1,2-丁二烯的标准偏差为0.51％，苯乙烯为0.88％，1,4-丁二烯单元的标准偏差为0.56％，反式-1,4-丁二烯的标准偏差为0.31％，0.68顺式-1，4-丁二烯单元的％。苯乙烯，1,2-丁二烯，1,4-丁二烯和反式-1,4-丁二烯的预测均方根误差（RMSEP）为0.15、0.29、0.29和0.28，R ²值为0.93分别为0.92、0.92和0.95，证明了将紧凑型仪器与有效的分析程序（如化学计量学）结合使用时，利用紧凑型仪器进行低场NMR光谱分析的潜力，以控制生胶的质量。