The vibrational spectra of some ethylene‐propylene copolymers

Abstract

IR‐ and RAMAN spectra of ethylene‐propylene copolymers are given, and their significance is discussed in terms of the structure of the “crystalline” units. It is concluded that vibrational spectroscopy is applicable to the structural diagnosis in this case, and that the addition of small amounts of propylene to ethylene alters the crystallinity in blocks of the latter to the less normal form containing only one chain per unit cell. In these particular cases, at lower ethylene concentrations normal crystallisation seems to occur in both ethylenic and propylenic sectors.