Two series of segmented polyurethanes, one containing 50% soft segments and the other with 70% soft segments were synthesized. Chemical crosslinks were introduced through the hard segment in a controlled way. Chemical polyurethane networks were characterized by swelling. The effect of the degree of
Physical properties of crosslinked polyurethane
β Scribed by Tsai, Yu-Min; Yu, Tzyy-Lung; Tseng, Yu-Hsien
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 111 KB
- Volume
- 47
- Category
- Article
- ISSN
- 0959-8103
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β¦ Synopsis
Polyester based polyurethanes were synthesized from low molecular weight polyester 2000) and 4,4@-methylene bis(phenyl isocyanate) (MDI) with (M n butanediol as a chain extender and glycerol as a crosslinker. The polyester was synthesized from adipic acid and glycol which was a mixture of 1,6-hexanediol and 1,2-propanediol. The e β ect of the crosslinker content on the degree of H-bond formation in the hard segments and the physical properties of polyurethanes were studied by di β erential scanning calorimetry (DSC), thermal mechanical analysis (TMA), Fourier transform infrared spectroscopy (FTIR) and mechanical testing. The experimental results revealed that incorporation of a triol crosslinker into the hard segments of polyurethane results in a decrease of hard segment H-bond formation. The mechanical data indicate that the mechanical properties of polyurethanes depend on the concentrations of physical and chemical crosslinks and that there is an optimum concentration of triol crosslinker for the tensile stress and elongation properties.
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