Fourier Transform Infrared Spectral Analysis of Polyisoprene of a Different Microstructure

Table 2

The explanation of absorption peaks of FTIR spectrum of polyisoprene.

Wavenumber/cm^−1	Attribution	Wavenumber/cm^−1	Attribution
3080	–C–H stretching vibration of carbon-carbon double bond in 1,2-unit	1150	Stretching vibration of CC main chain in trans-1,4-unit
3070	CH2 stretching vibration of –C=C– in 3,4-unit	1140	Stretching vibration of CC main chain in cis-1,4-unit
3035	CH stretching vibration of –C=C– in 1,4- or 1,2-unit	1044	Stretching or wagging vibration of CH3C=C in trans-1,4-unit
2727	Sympathetic vibration	1036	Stretching or wagging vibration of CH3C=C in cis-1,4-unit
1663	C=C stretching vibration of 1,4-unit	1003	Stretching vibration of C–C in 3,4-unit
1644	C=C stretching vibration of 3,4- or 1,2-unit	910	Out-of-plane bending vibration of CH2 in the –CH=CH2 (1,2-unit)
1413	Bending vibration of C–H in the =CH2 group of 3,4- or 1,2-unit	888	Out-of-plane bending vibration of CH2 in the –C=CH2 (3,4-unit)
1383	Scissoring vibration of CH3 in trans-1,4-unit	843	Out-of-plane bending vibration of C–H in the –CH=CH– group of trans-1,4-unit
1375	Scissoring vibration of CH3 in cis-1,4-, 3,4- and 1,2-units	837	Out-of-plane bending vibration of C–H in the –CH=CH– group of cis-1,4-unit
1325	Scissoring vibration of CH3 or CH in trans-1,4-unit	600	Torsion or twisting vibration of CCC group in trans-1,4-unit
1311	Scissoring vibration of CH3 or CH in cis-1,4-unit