回收聚碳酸酯製備可降解聚酯多元醇之研究與應用

Abstract

現今社會對於高分子的需求日漸增長，高分子對於現代社會經濟的發展帶來不可否認的好處，同樣的這些固體廢棄物也為環境帶來極大的影響，高分子在垃圾掩埋場和工業廢物中所佔的比例不斷增加。作為經濟持續增長和發展的產物，研究出如何將高分子材料有效再利用、回收的技術已是一項全球共同的挑戰。此外，由於近年來各國相關組織積極推動循環經濟，且基於綠色化學原則之理念，研究具有環境相容性的生物可降解高分子也被視為循環議題有利之解決方案。因此，本研究將同為廢棄物議題關注對象之聚碳酸酯材料，利用先前實驗室發表之胺解法將聚碳酸酯回收轉換之反應中間體，並透過開環聚合反應將生物可降解之聚己內酯軟段引入反應中間體，提高了高附加價值反應中間體之熱穩定性、再加工性等。生物降解高分子對於可持續性及環境友善的材料發展過程發揮了極為重要的作用，為傳統不可被生物降解的高分子提供了替代品。除此之外，為了符合綠色化學原則，本研究除了使用一鍋法以簡單方便的方式進行，更替換高效但對環境有害之金屬催化劑，建立一符合綠色化學原則之有機催化系統，此開環反應轉化率可達到97 %。最後也經由實驗證實，於反應中間體引入之聚己內酯軟鏈段與市售材料相比易於被脂肪酶降解，且降解前後之聚碳酸酯回收轉化聚酯多元醇皆符合國際標準規範ISO 10993對材料所制定之生物毒性標準。

Nowadays, the demand for polymers is increasing day by day, and the benefit to socioeconomic is undeniable. However, these resultant solid wastes also have a great impact on the environment. Most of the polymers end up in landfills. The traditional linear economic system has a great negative impact on the environment. As polymer recycling involves many complex issues, research on how to recycle polymer waste has become a very important topic. It is a global challenge to research how to reuse and recycle polymer materials. The problem of everlasting solid waste is also one of the main driving forces for the development of biodegradable polymers. Biodegradable polymers play an extremely important role in the development of sustainable and environmentally friendly materials, providing alternatives to traditional non-biodegradable polymers. Research on biodegradable polymers with degradability and environmental compatibility can provide a solution to the current environmental issues. Among them, aliphatic polyesters are considered as biodegradable materials with great potential. In this study, the polycarbonate, which is also the focus of the waste issue, was recovered and converted into versatile intermediates with high added value by the aminolysis method. Subsequently, the biodegradable polycaprolactone soft segment was introduced into the polymer intermediates through the ring-opening polymerization reaction, which improved the thermal stability and reprocessability of the polymer intermediates. In order to comply with the principles of green chemistry, often used high-efficiency but environmentally harmful metal catalysts were replaced by a newly developed benign organic catalytic system, in addition to using the one-pot method in a facile manner. This robust environmentally friendly catalytic system revealed that the conversion rate of the ring-opening reaction could be as high as 97%. It is important to note that the introduced polyester soft segment could be degraded by lipase. Moreover, the degraded small molecules were capable of meeting the biotoxicity standards established by international standard ISO 10993 for materials.