Low-frequency excitations in amorphous poly(vinyl acetate)

Raman-active modes have been detected in amorphous poly(vinyl acetate) in the frequency region 20–160 cm^?1. The low-frequency spectrum appears as a broad band for all three molecular weights examined. Spectra were recorded at two temperatures, 293 and 77 K, and found to show similar characteristics at both temperatures. The presence in solid amorphous polymers of broad structureless bands in general and their significance are discussed.