Graf R, Demco D E, Hafner S, Spiess H W
Max-Planck-Institut für Polymerforschung, Mainz, Germany.
Solid State Nucl Magn Reson. 1998 Sep;12(2-3):139-52. doi: 10.1016/s0926-2040(98)00058-7.
1H double-quantum (DQ) solid-state NMR spectroscopy under fast magic-angle spinning (MAS) is introduced as a new spectroscopic tool for the investigation of the structure and local chain dynamics of elastomers. Dipolar connectivities between the protons of the various functional groups can be directly established from the highly resolved DQ solid-state NMR spectra as is shown for a series of cross-linked poly(styrene-co-butadiene). More quantitatively, residual dipolar couplings within and between the functional groups are evaluated selectively from the build-up curves of the double-quantum signals in the limit of the spin-pair approximation. In particular, the CH-CH and the CH2-CH couplings of butadiene, which both act predominantly along the chain-segment direction, have been measured relative to the CH2 coupling. The total build-up intensity is correlated with the cross-link density.
介绍了在快速魔角旋转（MAS）下的1H双量子（DQ）固态核磁共振光谱，作为一种用于研究弹性体结构和局部链动力学的新光谱工具。如一系列交联聚（苯乙烯-共-丁二烯）所示，各种官能团质子之间的偶极连接性可以直接从高分辨率的DQ固态核磁共振光谱中建立。更定量地说，在自旋对近似的极限下，从双量子信号的积累曲线中选择性地评估官能团内部和之间的残余偶极耦合。特别地，相对于CH2耦合，已经测量了主要沿链段方向起作用的丁二烯的CH-CH和CH2-CH耦合。总积累强度与交联密度相关。
