DFT study of vibrational dynamics and structure of aminopropylsiloxane polymer

In this work, we investigated IR and Raman spectra from 400-1800 cm−1 of aminopropylsiloxane (APS) polymerized on PVC substrate at room temperature. Complete assignment of the vibrational spectra was carried out using density functional theory calculations with Becke's three-parameter exchange functional in combination with the Lee-Young-Parr correlation functional (B3-LYP) and standard 6-311++ G(d, p) basis set. The vibrational spectra were calculated for two different conformations of silicooxygen rings: ladder structure and cubic structure. Comparative analysis of calculated and measured spectra reveals that ladder structure has been formed at the surface of PVC support.