RESOLUTION OF CRYSTAL SPLIT FUNDAMENTALS OF POLYETHYLENE BY RAMAN DIFFERENCE SPECTROSCOPY

Raman difference measurements are reported for an oriented polyethylene solid-state" extrudate. The sample was found to be uniaxial at the center and nonuniaxial at the edge. Difference techniques lead to a resolution of the correlation split antisymmetric CC stretch (ν4(π)) and CH2 twisting (ν7(π)) fundamentals at room temperature. The splitting for the CH2 wagging (ν3(π)) fundamental is observed for the first time and the higher frequency component is unambiguously assigned to species B2g(ca). The degree of a axis orientation at the edge of the extrudate is estimated. © 1979 American Chemical Society."