Fourier Transform Infrared Spectral Analysis of Polyisoprene of a Different Microstructure

Table 3

The change of peaks of FTIR spectra according to the microstructure contents of polyisoprene.

Explanation∖peak value	Spectrum A	Spectrum B	Spectrum C	Note
Microstructure content
3,4-unit%	5	24	67	3,4-unit% increase by progressively
1,2-unit%	5	23	15	1,2-unit% increase by degrees
1,4-unit%	90	53	18	1,4-unit% decrease by degrees
Dissymmetry stretching vibration of –CH3	2962.125	2964.053	2965.982	Blue shift of peak (the value is 2978 cm^−1 in trans-1,4-unit)
C=C stretching vibration	1644.982	1644.018	1643.054	Red shift of peak
Scissoring vibration of CH3	1376.925	1374.997	1374.033	Red shift of peak (the value is 1383 cm^−1 in trans-1,4-unit)
Out-of-plane bending vibration of CH2 in the –C=CH2 (3,4-unit)	889.023	888.059	887.095	Red shift of peak
Out-of-plane bending vibration of C–H in the –CH=CH– group of 1,4-unit	836.955	840.812	848.849; (flat top)	blue shift of peak