Improvement of low-temperature damping performance by the control of three-dimensional network structure formed by renewable oil in modified waterborne polyurethane

Abstract

Waterborne polyurethane (WPUs) were synthesized with polytetramethylene ether glycol (PTMG), isophorone diisocyanate (IPDI) as the primary raw material, castor oil (CO) and dimethylolpropionic acid (DMPA) as the crosslinker and hydrophilic chain-extender, respectively. Three-dimensional networks were constructed in the molecular chain of the polymer by the introduction of castor oil. With the increase of CO contents, the WPUs prepared with more flexible segments and more points of intersection supporting the three-dimensional structure provided by castor oil have films with weak resistance to water, better elasticity, lower effective damping temperature, and better thermal resistance. Different homogeneity of the network structure was obtained, it was found that with the gradual unification of the structure, the tensile properties of the film were improved by about 25%, and the lowest effective damping temperature moved to −43.25 ​°C. The WPU films could be used as a material for low-temperature damping applications.

Keywords

• Waterborne polyurethane
• Castor oil
• 3D cross-linked network
• Low temperature damping coating