Study on the Modification of Waterborne Polyurethane by Tung Oil Anhydride-Ester Polyol

Abstract

Waterborne polyurethane (WPU) emulsions were prepared with Tung oil anhydride-ester polyol (TOAEP) as modifier via the acetone process. The structure, morphology, emulsion particle size, thermal property and mechanical property of the Modified WPU were investigated by FT-IR, SEM, Laser particle size analysis, TG and tensile test, respectively. The experimental results show that the modified WPU emulsion particle size increases along with the growth of weight content of TOAEP. Compared with the unmodified WPU emulsion film, water and toluene absorption of the modified WPU emulsion film have decreased significantly, indicating that water and solvent resistance are remarkably improved after the modification. Tensile test shows that the tensile strength of the modified WPU emulsion film increases with the content of TOAEP while the reverse is true for the elongation at break. The characteristic thermo-decomposition temperatures of WPU have been increased notably after modification by the introduction of TOAEP which indicates that the heat resistance has been improved after modification. Morphology analysis shows that the soft segment phase and hard segment phase in the WPU are more compatible after modification.