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標題: | 高效率回收聚碳酸酯至反應中間體 Highly Efficient Process of Recycling Polycarbonate into Intermediates via Aminolysis |
作者: | Li-Yun Chen 陳立昀 |
指導教授: | 鄭如忠(Ru-Jong Jeng) |
關鍵字: | 聚碳酸酯,回收,胺解,聚氨酯,綠色化學, Polycarbonate,Recycling,Aminolysis,Polyurethane,Green chemistry, |
出版年 : | 2018 |
學位: | 碩士 |
摘要: | 本研究探討使用聚碳酸酯 (Polycarbonate, PC) 為原料,利用胺解使聚碳酸酯轉換為反應中間體,用於聚合物之原料,透過此一鍋二步法,成功將PC轉化為Polyurethane (PU)。不同於現有的回收PC方法,使用胺類將PC分解為不同的hydroxyl-N,N'-diphenylene-isopropylidenyl biscarbamates (DP-biscarbamates),過程中並無需使用觸媒,免去純化的複雜步驟,並且在低於80 ℃的環境下,無高溫高壓的安全疑慮。
使用一級脂肪胺–Hexylamine (HA) 建立本系列胺解研究之模型,由IR、NMR證實透過溶劑選擇、反應當量、濃度及溫度的條件控制,能夠得到高選擇性產物 (~98%),並分析不同產物比例。依據選擇的雙胺鏈長短,得到不同長度之反應中間體–Bisphenol A (BPA) 與DP-biscarbamates中間體,將影響硬鏈段比例,從DSC可以觀察到,由PC轉化成的PU主要由BPA結構主導其性質,因BPA的甲基結構阻礙聚氨酯軟硬鏈段排列,使高分子趨於非晶相。因不易結晶的特性,使聚合物有柔軟 (~1100%)、強度較低的特性 (~2MPa),以及良好的透明度,在UV-vis測試中,擁有最佳90%以上的穿透率;本研究亦嘗試透過硬鏈段物理交聯,或是三官能基化學交聯的方式,強化由PC回收物合成的PU,成功改善回收聚氨酯之機械性質。 Chemical recycling of poly(bisphenol-A carbonate), (PC), into polyurethanes was studied by aminolysis of amine carbonylation reaction through a convenient two-step one-pot process in this work. Via a highly efficient and selective amine carbonylation reaction, PC was depolymerized by aliphatic diamines forming hydroxyl-N,N'-diphenylene-isopropylidenyl biscarbamates (hydroxyl DP-biscarbamates) as major interim prepolymers. This process provided a more efficient way to recycle PC under a mild condition below 80 ℃ in the absence of catalyst, and 100% of conversion, without the safety concerns of high temperature and high pressure condition. The process was based on a thorough model study between PC and n-hexylamine to come up with a precision transformation condition as our processing chemical basis. Based on the IR and NMR result, the condition for converting PC into BPA and hydroxyl-carbamate intermediates featuring for high selectivity (~98%) could be achieved. Both short- and long-chained prepolymers are prepared with their respective diamines, and the prepolymers are chain-extended with commercially available reagents such as diisocyanates to produce a variety of PU polymers. The properties of PU polymers are highly dependent on the PC depolymerized products (BPA and BPA containing carbamates), which tended to exhibit an amorphous state due to the molecular packing inhibited from the methyl structure of BPA. Owing to the lacking of crystallinity, the PUs exhibited elastomeric properties with high elongations of ~1100% in tensile test. On the other hand, the amorphous PUs exhibited the transmittance as high as 90% in UV-vis spectra. Consequently, through the crosslinking process physically and chemically, the properties of PUs were enhanced by overcame the drawbacks of reused raw materials. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/70825 |
DOI: | 10.6342/NTU201802599 |
全文授權: | 有償授權 |
顯示於系所單位: | 高分子科學與工程學研究所 |
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