International. In a paper recently published by Chinese scientists, aliphatic diamine sulfonate (AAS-Na) and liquefiable dipyl alcohol acid (LDMPA) were used to synthesize polyurethane in water (WPU) with excellent property.
The influence of the molar-COOH/-SO3Na ratio on the structure and properties of aqueous polyurethanes was characterized by IR, particle size analysis, DSC, DMA, apparent viscosity, water absorption, contact angle, traction, and peel resistance tests. It was found that with a decreasing molar-COOH/-SO3Na ratio of 10:0 to 3:7, the particle size of the water-based polyurethane emulsion decreased, while the apparent viscosity of the samples increased.
Increasing the sample storage module
The water absorption of the WPU films decreased, while the contact angle of the films increased. The tensile strength, elongation at break and peeling resistance of the samples increased. In addition, DMA results showed that the addition of AAS-Na increased the sample storage module. And the DSC results showed that with a decreasing molar-COOH/-SO3Na ratio of 10:0 to 3:7, the Tg of the soft segment changed at a lower temperature, indicating that the degree of microphase separation of the samples was increasing.
Source: www.sciencedirect.com
