| Summary: | 碩士 === 中國文化大學 === 化學工程與材料工程學系奈米材料碩士班 === 100 === The Olefin block copolymer (OBC) was pre-mixed with 0.2 phr dicumyl peroxide (DCP), 1.5 phr maleic anhydride (MA) and 0.5 phr hexamethylenediamine (HMDA) to form OBC-g-HMDA and OBC-g-MA at 165 oC Then, variable amounts of OBC, OBC-g-MA and OBC-g-HMDA were mixed with TPU at 200 oC to prepare OBC/TPU, OBC-g-MA/TPU and OBC-g-HMDA/TPU blends, respectively.
The results of FT-IR (Fourier transform infra-red spectroscopy) suggested that MA and HMDA were essentially grafted on OBC. The results from XRD (X-ray diffraction) experiments revealed that all blends with or without modification displayed similar diffraction patterns, indicating that the modification didn’t cause a visible change in the crystalline structure. TEM (Transmission electron microscope) images showed that the OBC-g-MA/TPU blends displayed significantly finer morphology. And the reduced particle size in the dispersed phase was better than that of OBC/TPU blends. From the result of DSC (Differential scanning calorimetry), the crystallization temperature of OBC increased 1 to 2 oC for OBC-g-MA/TPU blends in comparison with OBC/TPU blends due to TPU induced nucleation effect from TPU under enhanced specific interaction between OBC-g-MA and TPU. The result of TGA (Thermo gravimetric analyzer) revealed that the modified systems showed higher thermal stability than the unmodified systems over the investigated temperature range due to the enhanced interaction through inter-bonding and the usage of functionalized OBC. From tensile test, the tensile strength and Young’s modulus were higher for modified systems than those for OBC/TPU blends.
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