Production and analysis of highly monodisperse oligomeric Polyethylene Oxide

Synthesized polymers contain a distribution of different molecular weights. Even the most monodisperse synthetic polymers usually available have a polydispersity index (PDI) of about 1.01. Even these relatively monodisperse samples contain many different polymer chain components (N-mers). In this study, we produce highly monodispersed Poly(Ethylene oxide) through evaporative purification of a M_n 600 PEO sample with a relatively high PDI. The purified samples were studied with TOF-MALDI, differential scanning calorimetry (DSC), and optical microscopy. While the original polymer has a T_m of 294K, the melting temperature of separated products ranges from 265K to 296K. The T_m values are compared with Gibbs-Thompson predictions where the crystal size is determined by the number of monomers.