Abstract
The bond direction between fiber axis and N-H bond direction of $^15N$-Gly labeled silk fibroin fiber and poly-p-phenyleneterephthalamide(PPTA) oriented were obtained from the dipolar-bipolar interaction information, respectively. Theoretical method for the determination of molecular bond directions relative to the axis of fiber was derived on the basis of solid state nuclear magnetic resonance dipolar-dipolar interaction tensor. The oriented samples were placed parallel to the applied magnetic field, and the $^15N-^1H$ hetero-nuclear dipolar-dipolar splitting values were obtained. Substituting this values into the derived equation, the N-H bond angles ($$\theta$_NH$=83$^{\circ}$ and 97$^{\circ}$) are calculated. Also, the N-Hbond direcyions to fiber axis of PPTA are 44$^{\circ}$ and 67- These obtained values compared with the values from the angular dependation spectra simulation of oriented PPTA sample.
