dc.description.abstract | PU is a soft segment and hard segment block-type copolymer composed of alternating. Soft segments provide polyurethane soft property whereas hard segments offer the stiffness by hydrogen bondings. It can be achieved by adjusting the composition of its multi-function, applied quite widely, and in environmental awareness, the water-based PU (Waterborne Polyurethane, WPU) is using water to replace volatile solvents, dramatically reducing the use of solvents.
The laboratory in the past had discussed the ionic group effect on WPU’’s structure and physical properties in a series of studies. But did not discuss the diamine chain extender impact on the WPU, so this experiment will be designed to change different linear diamine chain extender, and then to test the impact of the WPU.
In test analysis, by using FTIR to observation WPU synthetic peaks which can determine the WPU has synthesized successfully, and the phase separation completely. By using TGA to find the degradation temperature. In the DSC test, only could find T1 which produced by the physical aging. Because the hard segment cannot the regular array, therefore could not find T2, T3 and Tg in the DSC test. DMA test results found that when diamine chain extender’s carbon numbers a few more (2-6), the polymer reduces the strength, but when the carbon number is 8, but will enhance the strength of the polymer. The carbon number from 2 to 4 for the chemical stucture of the comparison, which found that the carbon number is 3, the polymer strength will be reduced. In tensile mechanical properties test, it confirms the DMA test results once again, and to illustrate the mechanical properties increased may be due to the microstructure change .
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