Star polymers formed by MPEG reaction with diepoxides. The course of reaction

Following our earlier papers [1–7] on star formation from oligo(oxyethylene)alcoholates as arms precursors and diglycidyl ethers as core the course of reaction of monomethyl ethers of poly(ethylene glycol) (as alcoholate, MPEG-OӨ) and diglycidyl ether of neopentyl glycol (DGNG) has been studied. Epoxy groups (E) react not only with primary alcoholates (p-OӨ), from the starting MPEG, but also with secondary –OӨ (s-OӨ) emerging in this reaction. Concentrations of both kinds of alcoholates have separately been determined by 1H NMR. Direct measurements by 1H NMR of concentrations of reagents allowed to follow the stars formation and compare these results with kinetic data observed by MALDI-TOF-ms and SEC. There are two major different populations of the intermediately formed stars, namely with and without E. The former are much more reactive then the latter. It has been observed that for some stars the steady state appears, resulting from their fast formation and slow consecutive reactions.