- 學位論文
乙烯-醋酸乙烯酯製程衍生低聚物再生之研究
Reclamation of oligomer by-product in ethylene-co-vinyl acetate (EVA) manufacturing process
摘要
高壓聚合過程中，常有無法達到特定分子量之低聚物產生，並藉由分離器排出，而常見之低聚物對於產業而言可直接做為副產品進行販售，做為潤滑劑、脫模劑使用，亦可添加改質劑、硬化劑等製成熱熔膠、黏著劑等。而本研究之標的物為乙烯-醋酸乙烯酯聚合過程中產生之衍生物(低聚物)，其外觀呈現棕褐色並且含有粒狀之污染物，因為其外觀狀況不佳，使得無法進行再利用。 本研究以不同有機溶劑及常見之脫色材料進行低聚物淨化處理，使處理過的低聚物獲得較佳之外觀表現。實際作為係將乙烯-醋酸乙烯酯低聚物以有機溶劑進行溶解，並於溶解狀態下添加脫色材料進行混拌反應，之後進行各項材料之分離，以獲得淨化之乙烯-醋酸乙烯酯低聚物。 經實驗結果顯示，未淨化的乙烯-醋酸乙烯酯低聚物主要之金屬污染元素為Fe，並含有大量之醋酸乙烯酯，經由本研究程序淨化後，其金屬污染及醋酸乙烯酯已大幅去除。淨化後之乙烯-醋酸乙烯酯低聚物材料黏度下降，其差熱分析(differential thermal analysis (DTA))之吸熱強度趨緩，顯示經處理後之乙烯-醋酸乙烯酯低聚物較為潔淨，且具有較佳之再利用之潛力。
並列摘要
During a high-pressure polymerization process, oligomers that do not reach specific molecular mass are often generated, and they need to be removed using separators. For the industry, common oligomers can be directly sold as byproducts for being used as lubricants or release agents. They can also be converted into hot-melt adhesives (glues) or other types of adhesives by adding modifiers or hardeners. The research target compound of this study was the by-product (oligomer) generated from the polymerization of ethylene-co-vinyl acetate (EVA). This by-product is brown in appearance and contains granular pollutants, and it cannot be reused because of its undesirable appearance. This study utilized different organic solvents and common decolorizing materials to perform oligomer purification, thereby generating oligomers with desirable appearance. In the study procedures, EVA was first dissolved in an organic solvent and then mixed and reacted with a decolorizing material. Next, each component in the mixture was isolated to obtain the purified EVA oligomer. The results showed that the main metallic pollutant in the EVA oligomer was Fe. The oligomer also contained a large amount of vinyl acetate. After purification, most of the metallic pollutant and vinyl acetate were removed. Material analysis revealed that the purified oligomer exhibited reduced viscosity. In differential thermal analysis (DTA), the endothermic intensity of the oligomer also decreased. The study results indicate that the purified EVA oligomers processed using the proposed method is purer and exhibits high potential for reuse.