Monocomponent Waterborne Polyurethane Adhesives: Influence of the Crosslinking Agent on Their Properties

Abstract

To improve the properties of the monocomponent waterborne polyurethane (WPU) adhesives, a series of crosslinked WPU were prepared with trifunctional polyester polyol (P210) as crosslinking agent. The crosslinked WPU dispersions and their films were characterized by conventional methods. The adhesion property of the samples was measured from T-peel test of leather/WPU adhesive/leather joints. Compared with the linear one, the crosslinked WPU exhibited low viscosity, small particle size, and low surface tension. For crosslinked films, the thermal stability, water resistance and mechanical properties were remarkably enhanced. The experimental data of T-peel test indicated that the adhesive strength significantly increased to 4.8 KN/m by crosslinking up to the optimum crosslink index of 1.2 and then showed a small decrease with excess.

Keywords:

• Waterborne polyurethane
• adhesive
• mechanical property
• crosslinking

Acknowledgements

This work was financially supported by Jiangsu Planned Projects for Postdoctoral Research Funds (grant no. 0602037B), the fund of Jiangsu University (grant no. 06JDG076), the Natural Science of Jiangsu Education (grant no. 08KJB150004) and the Natural Science of Jiangsu Province (grant no. BK2008247).