- 學位論文
醇解回收汽車泡棉於木材膠合劑之應用
Application of glycolyzed recycled automobile PU foam on wood adhesive
摘要
廢棄汽車的坐墊泡棉係以聚氨酯(Polyurethane)作為主要成分，但因其體積較大、密度低、難分解的特性，以至於焚化爐及掩埋場均不易處理，因此亟需另尋其他辦法處理這些廢棄泡棉。本研究係以廢棄汽車坐墊泡棉作為原料，利用醇解(Glycolysis)進行降解以取得多元醇(Polyol)。後以傅立葉轉換紅外光譜，分析多元醇化學鍵結，並探討其他基本性質如黏度、分子量、羥價與固形分。並將多元醇重新與二異氰酸酯聚合作為合板與集成材的膠合劑，探討其可行性。研究結果發現，多元醇可運用分子量範圍約在9100至9850之間。利用傅立葉轉換紅外光譜的圖譜分析，了解醇解可將聚氨酯當中的NCO基團降解，產生聚醚多元醇(Polyether polyol)以及胺類化合物(amino group compound)。此等醇解物之黏度、分子量、羥價與固形分，皆會受到添加的二乙二醇(Diethylene glycol, DEG)量的影響。在與二異氰酸鹽(Methylene diphenyl diisocyanate, MDI)重新聚合時，較高的MDI/Polyol (w/w, %)比例，具有較高的膠合強度以及耐熱、耐水性。膠合劑用於合板熱壓製程時，70 ℃ 、15 - 20 min為較合適的熱壓條件，做為兩層同等級集成材的膠合劑時，其MOE約在6.5-7.5 GPa之間，MOR則是在50-56 MPa之間。若以台灣每年產生約六千餘噸廢棄汽車坐墊泡棉估計，若將其全數利用醇解製得多元醇而利用在木材膠合劑上，將有潛力取代目前常用之尿素膠或RF膠等，達到循環經濟的目的。
並列摘要
Automobile cushion foam is made based on polyurethane. Because of its bulk, low density and low degradability, it is difficult to be treated by current incinerators and landfills. There is an urgent need to find alternatives to treat waste automobile cushion foam. In this study, waste automobile cushion foam was glycolyzed by diethylene glycol (DEG) to obtain polyol. Then, the chemical bonding of polyols was analyzed by Fourier transform infrared spectroscopy (FTIR). Other basic properties such as viscosity, molecular weight, hydroxyl value, and solid fraction were also been analyzed. The feasibility of re-polymerizing polyol with methylene diphenyl diisocyanate (MDI) as an adhesive for plywood and glulam was also investigated. The study found that polyols can be used in the molecular weight range of approximately 9100 to 9850. FTIR revealed that glycolysis degraded isocyanate group of polyurethane to produce polyether polyol and amino group compound. The viscosity, molecular weight, hydroxyl value, and solid content of these polyols are affected by the amount of DEG added. Higher MDI/Polyol (w/w, %) ratio in the repolymerization with MDI result in higher bonding strength, heat, and water resistance. When the adhesive is used in the hot pressing process of plywood, 70 oC and 15 - 20 min are the more suitable hot-pressing conditions. When the adhesive is used in two-layer identical grade glulam, modulus of elasticity (MOE) are about 6.5-7.5 GPa. The modulus of rupture (MOR) are between 50-56 MPa. Under the estimation for about 6,000 tons of waste automobile cushion foam generated annually, glycolyzed polyol will have the potential to replace all the urea or resorcinol formaldehyde wood adhesive in Taiwan. By doing do could assist achieving the circular economy.