Theoretical study of glycidol hyperbranching polymerisation

Full Paper: Bulk hyperbranched anionic polymerisation of glycidol initiated by methoxide anion has been studied at B3PW91/6-311+G(2d,p)//HF/6-31G/d') and MP2/6-31+G(d')/MP2/6-31+G(d') levels of theory. The Isodensity Polarise d Continuum model was applied to take into account the environment effect. The results of molecular modelling are in good agreement with experimental data. According to the calculations glycidol polymerisation is thermodynami cally controlled. The attack on the unsubstituted glycidol end is thermodyn amically preferred except for the very first polymerisation step. Fast prot on exchange reaction takes place during the polymerisation giving rise to t he branching reaction. While the linear growth is caused by primary alkoxid e attack, the branching reaction occurs by secondary alkoxide attack on the next glycidol molecule. It was found that cyclisation reactions show highe r activation energies and are less favourable thermodynamically compared to polymerisation.