固体核磁共振法测定硫化丁苯橡胶中的苯乙烯

采用魔角旋转固体核磁碳谱法(MAS–~(13)CNMR)测定硫化丁苯橡胶中的苯乙烯含量。通过固体核磁碳谱解析,对丁苯橡胶中苯乙烯、1,2-乙烯基、1,4-丁二烯的特征峰进行归属分析,以固体核磁外标法定量。对已知苯乙烯含量的标准样品进行测定,绘制校正曲线,结果显示理论苯乙烯含量与固体核磁法计算结果成良好的线性关系,线性相关系数(r~2)为0.97。经标准曲线校正后的苯乙烯含量接近于真实值,计算结果的相对误差小于5%,测定结果的相对标准偏差为0.31%(n=6)。该方法适用于单一胶种的硫化丁苯橡胶中苯乙烯含量的检测。

Determination of Styrene in Cured Poly-Styrene-Butadiene Rubber by Solid State Nuclear Magnetic Resonance

Styrene in cured poly-styrene-butadiene rubber was determined by magic angle spinning solid states nuclear magnetic resonance. The characteristic groups of microstructures such as styrene, 1,4-butadiene, 1,2-vinyl were attributed. The content of styrene was calculated by 13CNMR. Standard cured poly-styrene-butadiene rubber samples were measured, and the calibration curve of the theoretical value and NMR result was obtained with the correlation coefficient (r2) of 0.97. The content of styrene calibrated by the calibration curve was closer to real value. The relative error was less than 5%, and the relative standard deviation was 0.31%(n=6). The method can be used for detection of styrene in cured poly-styrene-butadiene rubber.