利用超臨界二氧化碳合成甲基丙烯酸與阿魏酸共聚物之抗氧化性高分子材料

Abstract

近年來，許多研究開始利用超臨界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、食品方面之材料合成，其中，高分子型抗氧化劑的合成，第一次使用此綠色合成技術進行製備。 高分子型抗氧化劑材料，第一次使用超臨界技術進行合成，實驗的策略為利用綠色溶劑超臨界二氧化碳為溶劑，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，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，在65℃，20 MPa，24小時下，製備兩種結構的高分子型抗氧化劑，分別為線型共聚高分子PMAA-FA與網狀結構高分子PMAA-FA-EGDMA。 材料分析以傅立葉轉換紅外線光譜(FTIR)及紫外可見光光譜(UV-Vis spectrometer)分析材料化學性質，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法測試得抑制百分比，共聚型高分子抗氧化劑可得約89.4 %，網狀結構高分子抗氧化劑可得約72.9 %，與未添加抗氧化劑反應之高分子比較，發現抗氧化能力有明顯地提升；電子顯微鏡(SEM)觀察表面形貌，大小約為0.24~0.49 μm的聚集粉末。此兩種型式的高分子抗氧化劑材料，主要可應用於藥物或醫療方面。

The unique and tunable fluid properties of supercritical carbon dioxide have been used in polymer synthesis or polymer process recently, especially, the materials for medical, pharmaceutical, and food technology. In this work, polymeric antioxidants were synthesized for the first time in supercritical carbon dioxide. The strategy that using supercritical carbon dioxide as green solvent, methacrylic acid(MAA) as monomer, antioxidant ferulic acid(FA) as comonomer and ethylene glycol dimethacrylate (EGDMA) as crosslinker is suggested, and addition polymerization proceeded with initiator AIBN under supercritical carbon dioxide (65℃, 20 MPa, 24 hrs). The two forms of polymeric antioxidants, linear copolymer PMAA-FA and network polymer PMAA-FA-EGDMA, were obtained successfully. The chemical properties could be identified by FTIR, UV-Vis spectrums and 1H NMR, and the degradation temperature of polymeric antioxidants were studied by TGA. Antioxidant ability measured by DPPH assay of PMAA-FA and PMAA-FA-EGDMA performed about 89.4 % and 72.9 %. Compared with that of the control polymers synthesized in the absence of antioxidant molecules, the antioxidant activity of the two polymeric antioxidants was effectively elevated. SEM images showed the size of products were about 0.24~0.49 μm with aggregated morphology. The two forms of polymeric antioxidants could be useful in pharmaceutical and medical applications.