Natural Dimer Fatty Acids Based Waterborne Polyurethane: Thermal, Mechanical and Antihydrolytic Properties

Abstract

A series of waterborne polyurethanes (WPUs) based on polyester polyols derived from 0–70 wt% dimer fatty acids (DA) in dicarboxylic acid were prepared. The structures of WPU were characterized by attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. The effect of DA weight content on properties of WPU was systematically investigated by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact meter, tensile tester and chemical experiments such as immersion in alkaline solution. The results indicated the degree of microphase separation increased with the DA content. The incorporation of DA to WPUs increased thermal stability, surface hydrophobicity, water resistance and hydrolytic resistance. The WPUs with 10–40 wt% DA had excellent mechanical properties (tensile strength and elongation at break were 13.1 MPa and 726% for the WPUs with 20 wt% DA relative to 6.8 MPa and 605% for the WPUs with no DA, respectively).