Molecular structure characterization of hyperbranched polyesteramides

The molecular structure of a series of hyperbranched polyesteramides was st udied using size exclusion chromatography (SEC), mass spectrometry (MS) and small-angle neutron scattering (SANS). Products with increasing molecular mass were obtained through the polycondensation of in situ produced AB(2)-l ike monomeric units. Electrospray ionization MS indicates that narrow SEC f ractions consist of different isomers, the number of which increases with m olecular mass. Molecular mass moments and polydispersity numbers increase w ith polycondensation degree. The SANS measurements and SEC-DV data yield va lues for the polymers fractal dimension, which can be rationalized in the f ramework of percolation theory that originally was designed for randomly br anched polymers. Randomly branched polymer behavior in this particular case possibly results from a side reaction involving reactivity among B-end gro ups.