Synthesis and Characterization of Anionic Polyester-Polyurethane Dispersion as Environmentally-Friendly Water Based Resins

Abstract

Aqueous polyurethane dispersions (PUDs) have recently emerged as important alternatives to their 
solvent-based counterparts for various applications due to increasing health and environmental awareness (green 
chemistry). Anionic polyester-polyurethane dispersions were synthesized by three steps. In the first step, 
macromonomer diisocyanate having carboxylic acid was prepared by isophorone diisocyanate (IPDI), dimethylol 
propionic acid (DMPA) in percent of acetone as solvent and dibutyldtin dilaurate (DBTDL) as catalyst. Then, 
carboxylic polyurethane was prepared by reaction macromonomer diisocyanate having carboxylic acid with 
linear aliphatic polyester (Mw=2000), trifunctional polyester (Mw=2800) and butanediol (BDO) as chain 
extender. The next step involved neutralization and dispersion in water, where acidic polyurethane was 
neutralized by the addition of triethylamine (TEA). Factors influencing the synthesis of polyurethane dispersion 
mainly involve reaction temperature, reaction time, the concentration of catalyst, DMPA content and BDO 
content, were studied. The polymers have been characterized with DSC and FTIR.