Investigation of novel diethanolamine dithiocarbamate agent for RAFT polymerization: DFT computational study of the oligomer molecules

Abstract

This study presents the successes in polystyrene (PS) synthesis through reversible additional fragmentation chain transfer (RAFT) polymerization. For RAFT polymerization of styrene, diethanolamine (DEA) RAFT agent was used. The PS synthesis has made significant progress in the control of the molecular weight distribution of polymeric products. The average molecular weight between 37113 and 43183 g mol–1 of PS determined by gel-permeation chromatography (GPC) was consistent with the accounted values. The controlled polymerization system also exhibited first-order linear kinetics and produced PS with slightly high dispersity (Mw/Mn = 1.42). The RAFT agents and polymers were characterized by NMR and Fourier transform-infrared (FTIR) spectroscopies, GPC), and differential scanning calorimetry (DSC). Besides, the structural and electronic properties for monomer, trimer and hexamer molecules on the DEA RAFT agent series were performed by density functional theory studies. Energy gap (Δ) values for monomer, trimer and hexamer were found to be 4.0396, 4.0943 and 4.0010 eV, respectively. These results show the chemical activity in the series and the charge transferability within the polymer. In the same series, the dipole moment values increased in parallel with the chain growth, as μ(D) = 0.9124, 1.9951 and 2.0918, respectively.