Surface Modification of Polyesteramide-Based Hyperbranched Polymer Using

In this study a polyester amide-based hyperbranched polymer with hydroxyl end-groups is modified by the aid of acrylic acid. Replacement of hydroxyl groups by acrylic ones provide this potential for the hyperbranched polymer to be used in radiation curable systems. The modification is carried out through esterification reactions and various conditions such as reactants ratios and reaction times, leads to two different degrees of polymerization of 40% and 65%. Products characterizations are performed by Fourier Transformation Infrared (FT-IR) spectroscopy, Nuclear Magnetic Resonance (NMR) and Differential Scanning Calorimetry (DSC). Accordingly, with increase of conversion, the peaks position at 3200 3500 and 1730-1750 have decreased and increased respectively which shows the reduction of the concentration of hydroxyl and augmentation of concentration of ester carbonyl groups. Besides, based on the HNMR spectrum, appearance of three peaks in the range of 5.8 to 6.5 ppm confirms the existence of hydrogen atoms of acrylate groups in the modified hyperbranched polymer. Also, the influence of the hyperbranched polymer on the viscosity of Trimethylol Propane Triacrylate (TMPTA) is investigated. The results demonstrated that no significant changes in viscosity are detectable yet a slight increment in viscosity occurs.