三种测量橡胶交联密度的核磁共振方法比较

核磁共振（NMR）技术已经成为测量橡胶交联密度的一种常用技术手段．该文探讨了用于测量橡胶交联密度的三种NMR方法：¹H双量子（DQ）NMR、¹H Hahn回波和¹H CPMG回波，讨论了这些方法测量值差异的来源．在此基础上进一步研究了¹H CPMG回波方法中回波时间对测量值的影响，探讨了改善¹H CPMG回波方法的方案．

Comparison of Three NMR Methods for Measuring Crosslink Density of Rubbers

NMR is a frequently used technique for measuring crosslink density of rubbers. In this work, three commonly used proton NMR methods for measuring crosslink density of rubbers i.e., 1H double-quantum (DQ) NMR, 1H Hahn echo and 1H CPMG echo] were compared. Different approaches showed different results, and the origin of such discrepancy was discussed. The echo time dependence of the crosslink density measured with the CPMG echo method was studied. The ways to improve the CPMG echo-based measurements are discussed.