- 學位論文
磺酸化電活性環氧樹脂之製備、鑑定及其在防腐蝕塗料之應用研究
Preparation characterization of sulfonated electroactive epoxy and its application in anticorrosion coatings
摘要
本碩士論文的研究主軸聚焦在製備新型具高電活性的高分子，將其應用在金防腐蝕塗料上，並以電化學方式評估其金屬防蝕的效果。首先，利用氧化偶合法來合成具磺酸及不具磺酸之胺基封端苯胺三聚體(SACAT 及ACAT)，並以核磁共振光譜儀(1H-NMR)、複立葉紅外光譜儀(FTIR)及質譜儀(MS)對所合成的SACAT 及ACAT 進行化學結構鑑定。進一步將S-ACAT/ACAT 和環氧樹脂前趨體(Epon 828)在適當的溶劑下均勻混合，並與硬化劑(T403)進行開環聚合反應，即可得到磺酸化/非磺酸化電活性環氧樹脂。並進一步以FTIR 光譜確認環氧環(epoxide ring)已經打開與硬化劑中的一級胺基(primary amine)進行化學反應。所合成之磺酸化/非磺酸化電活性環氧樹脂之電活性(電催化能力)可進一步由電化學(循環伏安儀)及化學(紫外光- 可見光吸收光譜儀)進行監控。由研究數據顯示:相較於非磺酸化電活性環氧樹脂，磺酸化電活性環氧樹脂具有較佳的電催化特性。在電化學防腐蝕的測試上，量測所製備塗層的塔伏曲線(Tafel plot)、涅斯特曲線(Nyquist plot)及博德曲線(Bode plot)。由量測的結果顯示:相較於非磺酸化電活性環氧樹脂，發現磺酸化電活性環氧樹脂的塗層在冷札鋼上具有好的金屬防蝕效果，原因可能是磺酸化電活性環氧樹脂較佳的電催化效果可導致較緻 密鈍性金屬氧化層的生成，以保護下層尚未被腐蝕的金屬(如:鐵(Fe))。此鈍性金屬氧化層的生成可進一步由拉曼光譜(Ramanspectroscopy)來確認化學組成。
並列摘要
In this dissertation, electroactive epoxy polymer with higher redox capability was prepared and applied in corrosion protection coating,followed by investigated by a series of corrosion measurements in saline conditions. First of all, sulfonated/non-sulfonated amine-terminated aniline trimers (i.e., S-ACAT/ACAT) were synthesized by oxidative coupling reaction, followed by studied by proton-nuclear magnetic resonance (1H-NMR) spectroscopy,Fourier-Transformation infrared (FTIR) spectroscopy and mass spectroscopy. Subsequently, the electroactive epoxy resins with/without sulfonated group were prepared by homogeneously mixing S-ACAT/ACAT with epoxy precursor of Epon 828 under magnetic stirring, followed by reacting with hardener of T403 for three days to complete the epoxide ring-opening polymerization reactions and monitored by FTIR spectroscopy. The electroactivity of as-prepared electroactive epoxy coating with/without sulfonated group upon indium tin oxide (ITO) electrode was studied by electrochemical cyclic voltammetry and in-situ monitoring of chemical oxidation by UV-visible absorption spectroscopy. Researches showed that the electroactive epoxy coating with sulfonated group on ITO electrode exhibited more electroactivity as compared to that of electroactive coating without sulfonated group. For the corrosion protection of as-prepared electroactive epoxy coatings upon cold-rolled steel (CRS) electrode was studied by a series III of electrochemical corrosion measurements such as Nyquist plot, Tafel plot and Bode plot. The epoxy coating with sulfonated group upon CRS electrode was discovered to reveal excellent corrosion protection as compared to that of electroactive epoxy coating without sulfonated group. The better corrosion protection of electroactive epoxy coating with sulfonated group may be attributed to the corresponding higher redox capability, inducing more densely passive metal oxide layers (e.g., Fe2O3) formed upon the surface of metallic substrate. The passive metal oxide layers formed on the metallic substrate can be further identified by the studies of Raman spectroscopy.