| Summary: | 碩士 === 國立中央大學 === 化學工程與材料工程研究所 === 94 === According to our research in the past years, in the systems of nonpolar-based polyurethane, we think that owing to strong force at interface, hardsegments are restrained.Therefore,we have an idea that if relaxation of interface occurs, hardsegments can pack more orderly.In 2004, Lai modified poly-ip(hydroxyl terminated polyisoprene),which end-caped with various amount of polar lactone, as new polyols.Lai further synthesized a series of nonpolar-based segment polyurethanes, which were made from the new polyols, MDI(4,4´-diphenylmethane diisocyanate) and BD(1,4-butadiol).
In this study, we utilized TEM for direct observation of morphology of these segment polyurethanes.By analysizing a large number of micrographs, we found some changes from these nonpolar-based segment polyurethanes.For example, when hard content is 55%,the segment polyurethanes, whose soft segments are the modified poly-ip, show lamellar structure and the different departures.We combined the results of TEM with the results of DSC,DMA and tensile test,so that we could determine how the relaxation of interface affect the morphology and the properties.Finally, we also used succinic acid to modify poly-ip, as another new polyols,but that this new polyol reacted with MDI failed to form the prepolymer of segment polyurethane.
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