Hyperbranched polymers containing oxazoline monomers and succinic anhydride: applications in fast drying, low solvent coating formulations

Melt-polycondensation of succinic acid anhydride with oxazoline-based diol monomers gave hyper- branched polymers with carboxylicacids terminal groups. 1H NMR and quantitative 13C NMR spectroscopy coupled with DEPT-135 13 C NMR experiment showed high degrees of branching (over 60%). Esterification of the acid end groups by addition of citronellol at 160 ? C produced novel white spirit soluble resins which were characterized by Fourier transform-infrared (FTIR) spectroscopy, gel permeation chro- matography (GPC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Blends of the new hyperbranched materials with commercial alkyd resins resulted in a dramatic, concentration dependent drop in viscosity. Solvent-borne coatings were formulated containing the hyperbranched polymers. Dynamic mechanical analysis studies revealed that the air drying rates of the new coating systems were enhanced compared with identical formulations containing only commercial alkyd resins.