Raman Scattering in Crystalline Polyethylene

The Raman scattering in crystalline polyethylene, deuterated polyethylene, and n‐paraffins has been investigated as a function of temperature. Crystal‐field splitting of the $A_{\text{1G}}$ methylene bending mode observed at room temperature increases at − 160°C in both polyethylene and deuterated polyethylene. No splitting of the $B_{\text{2G}}$ skeletal stretching mode and the $B_{\text{3G}}$ methylene twisting modes in polyethylene is observed at room temperature, but the two components of the space group fundamental are resolved at − 160°C. Similarly, splitting of the $B_{\text{2G}}$ methylene wagging mode in deuterated polyethylene is observed at − 160°C but not at room temperature. The observed crystal‐field splittings are discussed in terms of splittings calculated from repulsive forces between hydrogen atoms on neighboring chains in the polyethylene crystal.