New hyperbranched poly(ether amide)s via nucleophilic ring opening of 2-oxazoline-containing monomers

An AB(2) monomer containing one oxazoline and two phenolic units was synthe sized. The polymerization of the monomer 2-(3,5-dihydroxyphenyl)-1,3-oxazol ine in N-methylcaprolactam resulted in a well-defined and fully soluble, hi gh molar mass, hyperbranched polymer with etheramide structure. The hydroly sis of some oxazoline groups as side reaction limits the achieved molar mas s when the polymerization is carried out in tetramethylene sulfone or in bu lk. The polymers were characterized by one (1D) and two (2D) dimensional H- 1 and C-13 NMR spectroscopy which allowed to determine the degree of branch ing to be 50% as expected from statistics. DSC and TGA measurements reveale d a glass transition temperature of 176 degrees C and a decomposition onset of 330 degrees C. The thermal ring-opening reaction was studied in situ by DSC measurements.