SYNTHETIC POLYISOPRENES STUDIES BY FOURIER-TRANSFORM RAMAN-SPECTROSCOPY

Fourier transform Raman spectra are presented for the cis-1,4 and trans-1,4 isomers of polyisoprenes. Vibrational intensities are used to determine quantitatively the amounts of each isomer in the microstructure. Improvements over previous work are suggested for the quantitative assessment of 1,4 microstructure. Also, changes in the Raman spectrum due to oxidative degradation show that preferential oxidative degradation for the vinyl-3,4 units occurs. The alpha and beta forms of trans-1,4 polyisoprene were studied and the v(C=C) bands resolved were identified 4 cm-1 apart. A study of the copolymerization of methyl methacrylate with isoprene showed that the 1,4 form is the most favoured form produced on copolymerization. Accurate cis-1,4 and trans-1,4 microstructural information could not, however, be determined.