A study on the structure of degraded PVC by photoacoustic spectroscopy

Photoacoustic spectroscopy (PAS) is used to study polyene structures in degraded PVC, and the PA spectra without deviation caused by solvents can be obtained. In the PA spectra, it is shown that polyenes with conjugated number n from 4 to 9 have definite absorption peaks in the 300-500 nm region. The relationship between the position of absorption peak lambda(max) and conjugated number n is discussed. Analyses of PA spectra combined with FTIR spectra enable an investigation of structural influences of some stabilizers. The influences on conformation interfere with the propagation of polyenes and give PVC extra thermal stability. (C) 1997 Elsevier Science B.V.