| Summary: | 碩士 === 國立臺灣大學 === 材料科學與工程研究所 === 85 ===
Blend of a low-density polyethylene (LDPE) and propyl ester phosphazene (MFR) of various component ratios were prepared melt mixing in a laboratory-scale brabender internal mixer.
Fractured surfaces of these blends were examined by means of scanning electron microscope and Tg value for the blends (as observed from DMA) were found compatible a few.
Crystallization dynamics and morphology of blend compositions has been investigated by DSC, X-ray and polar optical microscope. Isothermal crystallization was made experiments, When blenden with variable amount of MFR, the crystallization temperature of LDPE, Tc, were almost constant, n value of Avrami equation were decreased (but still be spherulitic). Crystallinity was increased slightly in these blend compo-sitions that Crystal arrangement was easy due to MFR making LDPE overall viscosity down, oversll crystallization rate also were increased, nuclei density was increasing few, especially LDPE20F was best than another compositions.
But slow dooled properties was in contract to iosthermal crystallizations. Crystallinity of LDPE which has been additive variable amount of MFR was inhibited in long time.
Physical property measurements are used by FTIR, TGA, Tensile Strength, LOI and Smoke Density test. Thermal degradation analysis and flammable properties indicated that such blends that amount of MFR in LDPE raise smoke density few, higher LOI value, higher degradation temperature and much more char yields than LDPE0F.
Mechanical characteristics had a lower modulus, ultimate strength and elongation at break than pure LDPE content, until be stoped in LDPE20F
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