| Summary: | 碩士 === 義守大學 === 生物技術與化學工程研究所碩士班 === 93 === In this work, we attempted to study crystallization kinetics of cross- linked poly(butylene succinate) (PBSU). PBSU can be effectively cross- linkked by adding a peroxide, t-butyl perbenzoate (BPB), into the polymer matrix. It was found that crystallization rate decreased with increasing BPB concentration. In isothermal crystallization, the n values in Avrami equation were close to 3 and the k values decreased with increasing BPB concentration. PBSU exhibited two endotherms in DSC thermograms upon melting. The high melting endotherm corresponded to melting of the crystallites re-crystallized from melting of those crystallites in the lower endotherm. In addition, both chemical and physical foaming of crosslinked PBSU were also studied. The foam pieces from chemical foaming had higher density and the cells were mostly closed. Foam pieces of very low density and very fine cellular structure could be obtained by high pressure CO2 foaming (physical foaming). The cells were mostly open, with a open-cell ratio higher than 90%. Unlike chemical foaming, the processing window became narrower as the crosslinking level had been increased in a CO2 foaming process.
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