| 摘要: | 在提倡環保的環境下，如何對用量最多的聚酯進行綠色發展是產業發展上的重要趨勢。過往評估報告顯示，聚酯的回收率較低，且回收後製成的產品價值往往不比當初，這就是目前聚酯環保化遇到的難處。聚酯中用量較多的為聚對苯二甲酸乙二酯（polyethylene terephthalate，PET）及聚對苯二甲酸丁二酯（polybutylene terephthalate，PBT），由於聚酯的回收困難，從原料端進行改質是決定聚酯品質及能回收與否的重要製程。合成一直以來都是聚酯製造的主要方法，能透過添加物提高聚酯性能的同時，也能從該手段中尋找能夠回收的可能性。過往研究就發現能透過醇解或水解方式解聚，在重新進行聚合，達到回收的目的。而共聚單體的選用中我們發現聚碳酸酯（polycarbonate，PC）中的碳酸乙烯酯(Ethylene carbonate，EC)，該單體能經由使用二氧化碳進行製造，這兩點讓我們看到環保的可能性。因此，本研究以自行設計的合成設備進行合成，一部分使用酸加醇聚合形成聚酯，另一方面使用EC與醇類進行聚合形成脂肪族聚碳酸酯，透過導入PC結構於PBT後，在確認比例酸及EC比為1:1時，該共聚物不僅具有一定的CO2用量也有CO的含量，且不會過於影響PBT整體性質後，也利用該配比，使用不同酸醇進行共聚，最後製備一系列聚酯共聚物，使用FT-IR及XRD鑑定合成產物結構，接著使用TGA、DSC及DMA確定合成產物結構穩定性，最後利用接觸角及吸水性測試探討合成產物的物理性質。研究結果發現EC加入後，PC結構中的C-H基團被對苯二甲酸的不對稱伸縮振動取代，證實EC加入不會影響PBT主結構，而是可以形成PBT與PC共存的新型聚酯共聚物。X光繞射分析結果顯示EC含量增加導致聚合物結晶度降低，且共聚物中使用對苯二甲酸(Terephthlic acid, TPA)進行共聚的聚酯共聚物擁有相對多的晶格平面存在。DSC結果也顯示結晶度的下降與EC含量相關，且透過DSC、TGA及DMA的測試結果發現，Tm、Td、Tg，皆隨著EC的加入後下降，但使用TPA進行聚合的聚酯共聚物熱性質下降幅度較小，依然保持與聚酯相當的結構穩定性，這也間接顯示了苯環結構對於聚酯是相當重要的存在。EC的添加會導致聚酯共聚物結構鬆散，除了會使合成產物較容易於施加外力容易變形外，水分子容易進入結構內部，這也讓接觸角度下降，吸水性上升，這邊發現由於聚酯結構與水分子的相斥，導致親水性極低，透過與PC共聚後雖然熱性質有些微下降，但整體而言，不只提供了聚酯環保性，也間接改善了親水性的問題。
In an environment that promotes environmental protection, how to carry out green development of polyester, which is the most widely used, is an important trend in industrial development. Past evaluation reports show that the recycling rate of polyester is low, and the value of the products made after recycling is often not as good as the original. This is the current difficulty in environmentally friendly polyester. The most commonly used polyesters are polyethylene terephthalate and polybutylene terephthalate. Due to the difficulty in recycling polyester, modification from the raw material side determines the quality of the polyester and whether it can be recycled. important process. Synthesis has always been the main method for manufacturing polyester. While the performance of polyester can be improved through additives, the possibility of recycling can also be explored through this method. Past research has found that it can be depolymerized through alcoholysis or hydrolysis, and then polymerized again to achieve the purpose of recycling. In the selection of comonomers, we found ethylene carbonate in polycarbonate. This monomer can be produced by using carbon dioxide. These two points allow us to see the possibility of environmental protection. Therefore, this study uses self-designed synthesis equipment for synthesis. One part uses acid and alcohol polymerization to form polyester. On the other hand, EC and alcohols are used to polymerize to form aliphatic polycarbonate. After introducing the PC structure into PBT, After confirming that when the proportional acid and EC ratio is 1:1, the copolymer not only has a certain amount of CO2 but also a CO content, and will not affect the overall properties of PBT too much, this ratio is also used to copolymerize using different acids and alcohols, and finally Prepare a series of polyester copolymers, use FT-IR and XRD to identify the structure of the synthesized products, then use TGA, DSC and DMA to determine the structural stability of the synthesized products, and finally use contact angle and water absorption tests to explore the physical properties of the synthesized products. The research results found that after the addition of EC, the C-H groups in the PC structure were replaced by the asymmetric stretching vibration of terephthalic acid, confirming that the addition of EC will not affect the main structure of PBT, but can form a new polyester copolymer in which PBT and PC coexist. X-ray diffraction analysis results show that the increase in EC content leads to a decrease in polymer crystallinity, and the polyester copolymer copolymerized with terephthalic acid has relatively many lattice planes. The DSC results also show that the decrease in crystallinity is related to the EC content, and the test results of DSC, TGA and DMA found that Tm, Td, and Tg all decreased with the addition of EC, but the polyester copolymerized using TPA The decrease in physical and thermal properties is small, and the structural stability is still comparable to that of polyester. This also indirectly shows that the benzene ring structure is very important to polyester. The addition of EC will cause the structure of the polyester copolymer to be loose. In addition to making the synthetic product easier to deform under external force, water molecules can easily enter the structure, which also reduces the contact angle and increases the water absorption. It is found here that due to the polyester The repulsion between the structure and water molecules results in extremely low hydrophilicity. Although the thermal properties are slightly reduced after copolymerization with PC, overall, it not only improves the environmental protection of polyester, but also indirectly improves the problem of hydrophilicity. |
