抗氧化劑能與人體內或食物中的自由基起作用，穩定自由基，避免自由基與其他分子反應，且高分子型抗氧化劑具有較高的穩定性及較緩慢的分解速率，因此將抗氧化劑固定於高分子鏈上可降低抗氧化劑的擴散損失。近年來，許多研究應用超臨界二氧化碳(Supercritical carbon dioxide, SCCO2)流體特殊的物理性質，當作材料合成、加工的媒介，特別是用於醫藥、食品方面之材料。上一年度，本研究室也利用此綠色合成技術，將抗氧化劑以共聚合反應連接到高分子材料主體，以偶氮二異丁腈(AIBN)當作起始劑，甲基丙烯酸(MAA)為單體，小分子抗氧化劑阿魏酸(FA)為共聚單體，製備了線性高分子型抗氧化劑PMAA-FA共聚物，得到初步良好的結果。有鑑於此，本計畫將繼續針對抗氧化劑改質方法做更深入的研究，其中，以交聯劑二甲基丙烯酸乙二醇酯(EGDMA)，進行自由基加成聚合反應，製備網狀結構的高分子型抗氧化劑 PMAA-FA-EGDMA，以期能得到網狀結構高分子抗氧化劑之材料，這兩種型式的高分子材料，各自可分別應用於不同的領域，線型共聚物可應用於血液透析膜，抗發炎敷料，或包裝材料等，而網狀結構高分子，則可應用於當作易氧化藥物的載體。本研究將探討利用高壓設備，以SCCO2為溶媒，使用超臨界技術進行合成高分子型抗氧化劑材料，製備網狀結構的高分子型抗氧化劑 PMAA-FA-EGDMA。第一年的研究，將已建立的超臨界流体反應設備，製備網狀結構高分子PMAA-FA-EGDMA，並利用傅立葉轉換紅外線光譜(FTIR)作產物分析及紫外可見光光譜(UV-Vis spectrometer) 作含量分析，核磁共振氫譜(1H NMR)鑑定共聚物之化學結構；熱重分析(TGA)測量材料熱裂解溫度(Td)；抗氧化性質分析以DPPH法測試得氧化抑制百分比；熱重分析(TGA)測量材料熱裂解溫度(Td)；電子顯微鏡(SEM)觀察表面形貌。本研究第二年，進一步深入探討反應參數如起始劑濃度及反應物單體濃度等反應因素對產物物性的影響，並尋求反應槽SCCO2的壓力、溫度及時間等最適操作條件，將實驗數據進行歸納分析，將可整理出超臨界共聚合反應的研究參數關聯性與最適化關鍵因素，評估實際應用的可能性並作為相關研究的參考。
Antioxidant can react with free radical to avoid the reaction of free radical with other compounds. And antioxidant in a polymer form is more stable and can slow down the releasing rate. Copolymerization of antioxidant with a polymer can also reduce the diffusing lost of antioxidant. Last year, for the sake of avoided solvent residue and environmental protection, the reaction of an antioxidant with a monomer to form a copolymer product by using supercritical carbon dioxide (SCCO2) as green solvent is studied by our laboratory. The addition polymerization proceeded by using 2,2’-Azobisisobutyronitrile (AIBN) as initiator, methacrylic acid (MAA) as monomer and antioxidant ferulic acid (FA) as comonomer, a linear copolymer PMAA-FA was obtained successfully. In this project, the copolymerization reaction of antioxidant by using supercritical fluid technology will be extended. By using ethylene glycol dimethacrylate (EGDMA) as crosslinker, the network form of polymeric antioxidant PMAA-FA-EGDMA will be synthesized, this network form of polymeric antioxidant could be useful in pharmaceutical and medical applications. In the first year of this study, the addition polymerization reaction to produce network copolymer in SCCO2 will be investigated, the network form of polymeric antioxidant PMAA-FA-EGDMA will be synthesis. The chemical properties of the result product can be identified by FTIR, UV-Vis spectrums and 1H NMR, and the degrading temperature of polymeric antioxidant is studied by TGA. Antioxidant ability is measured by DPPH assay. And SEM images will show the size and morphology of products. In the second year, we will also investigate the effects of concentrations of initiator, antioxidant and monomer reactants. Moreover the effects of the operation factors such as the temperature, pressure and reaction time period in SCCO2 will also be studied. The operation conditions and the reaction parameters will be optimized through this investigation. The results for optimal operation conditions are expected that are valuable to future industrial applications.
