磺酸化電活性聚脲之製備、鑑定及其在防腐蝕塗料之應用研究

本碩士論文之研究主軸為具磺酸基團電活性聚脲之合成、鑑定及其應用研究，並以電化學方法探討其應用於金屬防腐蝕塗料之成效。首先，利用二苯胺(或鄰磺酸對苯二胺)與苯胺進行化學氧化偶合法，以合成胺基封端苯胺三聚體(Amine-Capped Aniline Trimer ; ACAT)與胺基封端磺酸化苯胺三聚體(Amine-Capped Sulfonated Aniline Trimer; S-ACAT)。進一步以核磁共振光譜儀(1H-NMR)、傅立葉紅外光譜儀(FTIR)及質譜儀(MS)對所合成之ACAT/S-ACAT進行化學結構鑑定與比較。並利用電化學循環伏安儀(CV)量測兩單體之電活性(氧化還原能力)，由研究數據顯示: S-ACAT較ACAT具有較佳之電活性。接著，將先前所合成之ACAT與S-ACAT分別導入於聚脲之聚合反應中，以合成一系列之電活性聚脲(具磺酸及不具磺酸)，並進一步以FTIR確認電活性高分子的聚合反應，並以熱失重分析儀(TGA)、動態機械分析儀(DMA)、微差掃描卡計(DSC)、水滴接觸角(CA)做高分子的材料性質檢測。並利用電化學方式(如:CV)及化學監測方式(如:紫外光-可見光吸收光譜儀(UV-visible absorption spectroscopy))來評估並比較具磺酸化/不具磺酸化電活性聚脲之氧化還原能力。由研究數據顯示:具磺酸化電活性聚脲比不具磺酸化電活性聚脲有較佳的氧化還原能力(電催化能力)。在電化學防蝕的測試方面，探討所合成的高分子塗料以塔伏(Tafel)曲線、涅斯特(Nyquist)曲線及博德(Bode)曲線測試之後的結果。由數據資料顯示: (1)電活性的聚脲塗層較非電活性的聚脲塗層有較佳的金屬(如:冷扎鋼)防蝕效果; (2)具磺酸化電活性聚脲塗層比不具磺酸化電活性聚脲塗層有較佳的金屬防蝕效果。此原因可解釋如下:電活性的聚脲塗層具電催化能力，可在金屬表面產生緻密的鈍性金屬氧化層以保護下層未腐蝕之金屬，因此金屬防腐蝕能力較非電活性的聚脲塗層好。其次，具磺酸化電活性聚脲塗層比不具磺酸化電活性聚脲塗層有較佳的電催化能力，對金屬表面可產生更緻密的鈍性氧化層。所產生的鈍性氧化層(如: Fe2O3及Fe3O4) 的位置及強度可由萊曼光譜(Raman spectroscopy) 進一步證實。

關鍵字

電活性防腐蝕；苯胺三聚體；磺酸化；聚脲

並列摘要

In this dissertation, the synthesis, identification and properties of electroactive polyurea (EPU) with/without sulfonate groups were presented, and followed by applied in corrosion protection of metallic substrates. First of all, amine-capped aniline trimer (ACAT) and sulfonated amine-capped anilne trimer (S-ACAT) were synthesized by oxidative coupling reaction, followed by characterized by Proton-nuclear magnetic resonance (1H-NMR), Fourier-transformation infrared (FTIR) and mass spectroscopy (MS). Redox capability (i.e., electro-catalytic property) of as-prepared ACAT and S-ACAT monomer was identified by electrochemical cyclic voltammetry (CV). The S-ACAT was found to exhibit better redox capability as compared to that of ACAT based on the CV studies. For the preparation of EPU, the synthesis of polyurea was performed in the presence of specific amount of ACAT and S-ACAT. The as-prepared electroactive polyurea with/without sulfonated treatment was characterized by FTIR spectroscopy. The properties of as-prepared materials were investigated by thermogrametric analysis (TGA), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and contact angle (CA) measurement of water droplets. The redox capability of as-prepared EPU was identified by electrochemistry approach (CV) and non-electrochemistry approach (UV-visible absorption spectroscopy). It should be noted that the redox EPU with sulfonated groups was found to reveal higher redox capability as compared to that of EPU without sulfonated group. For the corrosion protection studies of cold-rolled steel (CRS) electrode coated with as-prepared coating materials, standard electrochemical corrosion measurements (such as Tafel plots, Nyquist plots and Bode plots) were used to investigate. It should be noted that the studies showed that all EPU coatings were found to display better corrosion protection on CRS electrode as compared to that of non-EPU coating. Moreover, EPU coatings with sulfonated group was found to reveal better corrosion protection as compared to that of EPU coating without sulfonated group. The possible reason might be attributed to that the redox capability of EPU may induce the formation of densely metal oxide layer upon CRS electrode to protect the underlying metal substrate. Moreover, the higher redox capability of EPU coating with sulfonated group as compared to EPU coating without sulfonated group may lead to the more densely metal oxide layer upon CRS electrode, as evidenced by the characteristic peak of Fe2O3 and Fe3O4 of Raman spectroscopy.

並列關鍵字

electroactive ； corrosion ； aniline trimer ； sulfonated ； polyurea

參考文獻

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磺酸化電活性聚脲之製備、鑑定及其在防腐蝕塗料之應用研究

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