Coumarin-based random copolymer

Abstract

In this article, coumarin-based random copolymer which can be utilized for atom transfer radical polymerization was investigated both theoretically and experimentally. The thermal degradation mechanism and the activation energies ( Ea) were obtained by means of the Coats–Redfern (CR), Tang, and Flynn–Wall–Ozawa (FWO) methods. The thermal degradation reaction mechanism for random copolymer obeyed the phase boundary model (contracting volume, R3) of solid-state mechanism. The thermodynamic properties in the range from 100 K to 500 K have been obtained. The calculated HOMO–LUMO energy gap and electronic properties, such as chemical hardness ( η), electron affinity ( A), chemical potential ( μ0), global softness ( ζ), electronegativity ( χ), global electrophilicity ( ω), and dipole moment ( μ), were investigated and discussed. The molecular electrostatic potential analysis of the random copolymer was also computed.

Theoretical DFT interpretation of infrared spectra of biologically active arabinogalactan sulphated derivatives

“…Irregular structure and the coexistence of various functional groups in different substituents positions coupled with tautomeric forms make accurate interpretation of arabinogalactan and its sulphated derivative IR spectra very difficult or almost impossible without clear insight of macromolecule structure and to establish spectral-structural correlations. Combination of the state-ofthe-art density functional theory (DFT) and calculations of model molecules with experimental AG and its sulphated derivatives IR spectra makes it possible to overcome these difficulties, to identify spectral band structure, interpret molecular structure like exact positions of sulphate groups and to determine basic biological properties of the macromolecules (Akman 2017, Barsberg 2010, Shanura Fernando et al 2017, Tran et al 2018.…”