Hyperbranched alkyd resins (HBRA) were synthesized by modification of hydroxylated hyperbranched polyester (HBP1-4) with tall oil fatty acids (TOFA). The core is a hydroxylated hyperbranched polyester of fourth generation with OH groups in the periphery (18), which is endcapped with tall oil fatty acids. The occurrence of these reactions, HBP1-4 and TOFA, was determined by making use of acid value, nuclear magnetic resonance, and hydroxyl values. The effects of TOFA and HBP1-4 on properties of the HBRA resins were investigated by vapor pressure osmometry, differential scanning calorimetry, thermogravimetric analysis, friction resistance, and hardness. The resins with higher modification percentage (HBRA4) presented the best thermal and hydrolytic stability, but lower friction resistance and hardness. All HBRA resins presented amorphous characteristics, OH groups, and double bonds in the periphery.

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Hyperbranched polyesters (HBPs) of fourth and fifth generation were synthesized by procedures involving one step (HBP4, HBP5), step by step (HBP4P, HBP5P), and combination of both of them (HBP1-4, HBP1-5) using 2,2-bis(methylol)propionic acid (DMPA), pentaerythritol (PE), and acid catalysis. The characterization of the polyesters was done by nuclear magnetic resonance (NMR), rheology on solution, Fourier transform infrared spectroscopy (FTIR), and acid and hydroxyl values. The degree of branching of polyesters (DB) and the average molecular mass and polymerization degree NMR were calculated by Frey and Fréchet methods and (DP) NMR , respectively, being higher for HBP4P sample. The molecular structure of polyesters depends mainly on of the synthesis method. The hydroxyl values were larger than 430 mg/g KOH for all HBPs, and the conversion was controlled between 90 and 93% to avoid excessive cyclization reactions. The steady shear viscosities at different temperatures and at 41.77 s À1 shear rate were measured for all HBPs solutions in dimethyl formamide (DMF) showing a shear thickening behavior. The flow activation energies (E a ) were calculated by Arrhenius equation.

Hydroxylated hyperbranched polyester (HBPs) of fourth and fifth generation were obtained by three methods; one step (HBP4, HBP5), step by step (HBP4P, HBP5P) and combinations of one step and step by step (HBP1-4, HBP1- 5). The HBPs were synthesized in bulk from 2,2-bis(hydroxymethyl)propionic acid (DMPA) and pentaerythritol (PE) using acid catalysis (p-toluenesulfonic acid) and characterized by infrared analysis, 1H and 13C nuclear magnetic resonance, gel permeation chromatography, vapor pressure osmometry, electro spray ionizationmass spectrometry, dynamic light scattering, refractive index, thermogravimetric and differential scanning calorimetric analysis. The refractive index of HBPs were low, the infrared and nuclear magnetic resonance analysis showed evidence of the occurrence of reaction between from 2,2-bis(hydroxymethyl) propionic acid (DMPA) and pentaerythritol (PE). The molar mass values of the HBPs determined by gel permeation chromatography were different to vapor pressure osmometry measurements due to small hydrodynamic volume of the HBPs. The mass spectrometry analysis showed different acyclic and cyclic units in the HBPs. The distributions of HBPs studied by dynamic light scattering were monomodal in number and volume and bimodal in intensity. The thermal stability of the fifth generation HBPs was higher than that the fourth generation. All HBPs presented amorphous behavior

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