URETHANE-MODIFIED ALKYD RESIN BASED PAINT PRODUCTION: DETERMINATION OF PAINT PROPERTIES

Alkyd resins have an important place among the binders used in the paint industry. One of the major advantages of alkyd resins is that they are susceptible to various modifications to gain the desired properties. In this study, urethane-modified alkyd resins were synthesized at different modification ratios using toluene diisocyanate as a modifier. The resin with the determined optimum modification ratio was used as the binder resin in the paint formulation. In the synthesis of four-component alkyd resin with 50% oil length, phthalic anhydride, tall oil fatty acid, trimethylolpropane, and dipropylene glycol were used. The synthesis of urethane-modified alkyd resins (R-UA-1/1, R-UA-1/2, and R-UA-1/3) was carried out by modification reactions of the prepared alkyd resin with TDI at different NCO/OH (1/1, 1/2, 1/3) molar ratios. Characterization of modified resins was performed by Fourier transform infrared spectroscopy. Subsequently, the optimum NCO/OH ratio was determined due to the physical and chemical surface coating properties and thermogravimetric analysis results of the resin films. The best results were obtained in the resin, where the modification ratio was NCO/OH: 1/1. Then, the urethane-modified alkyd resin (R-UA-1/1) prepared in this ratio was used as a binder in the solvent-based paint formulation. The wet/dry paint properties and household chemical resistance properties of solvent-based paint (B-1/1), prepared using urethane-modified alkyd resin, were examined with tests according to the standards, and the coating performance of this paint was determined in detail. As a result, durable coatings that are suitable for interior applications and can compete with alkyd paints were obtained from the paint prepared with urethane-modified alkyd resin.