Conformation effects in the XPS valence band spectra of aliphatic polyesters

XPS valence band spectra are reported for seven aliphatic polyesters. By comparison of the spectra with that of PMMA a qualitative understanding of the spectral features is achieved. By comparing valence band spectra of semi-crystalline solid and polymer melt samples, chain conformation effects are identified for five of the polyesters. For four of these the effects may be attributed to changes in methylenic hyperconjugation interactions on melting but the fifth contains (CH2)n segments that are too short for methylenic hyperconjugation to occur. Only one of the polyesters showed a significant conformation effect in the C 1s spectrum.