仿生超疏水電活性聚亞醯胺塗料及電活性聚亞醯胺/石墨烯複合材料之製備與防蝕性質研究

Advanced Anticorrosion Coating Materials Prepared from Biomimetic Superhydrophobic Electroactive Polyimide and Electroactive Polyimide / Graphene Composites

呂欣怡(Hsin-I Lu)

指導教授 ： 葉瑞銘

中原大學/理學院/奈米科技碩士學位學程/碩士(2013年)

https://doi.org/10.6840/cycu201300538

摘要

本論文成功合成出具穩定的半氧化半還原態之胺基封端苯胺三聚體(ACAT)，並與非共平面之二酸酐BSAA兩者合成電活性聚亞醯胺 (EPI)，將其材料之研究內容分為兩個部分:
第一部分探討利用模板複印法來仿造千年芋表面結構，製備超疏水電活性聚亞醯胺(SEPI)，材料本身具有氧化還原能力經模板複印使材料具有超疏水特性達到排水效果提升防腐蝕能力。研究中探討超疏水電活性聚亞醯胺材料之基本鑑定、接觸角和防腐蝕性質。使用接觸角量測儀量測其薄膜之接觸角，得知合成出超疏水電活性聚亞醯胺接觸角上升約70˚，防腐蝕方面利用循環伏特安培儀(CV)及交流阻抗模組(Impedance)，可以觀察到當仿千年芋結構之電活性聚亞醯胺，防腐蝕效果較佳。由於材料具有導電性，將材料塗佈在金屬表面會產生電荷轉移，使塗料和金屬間產生鈍性氧化層，本研究利用SEM和X射線光電子能譜儀(XPS)證明鈍性氧化層的生成。
本研究第二部分探討所製備之奈米複合材料在添加不同比例的石墨烯下之防腐蝕性質及氣體阻隔性質。首先將石墨烯以廣角X-ray繞射儀(WAXRD)觀察石墨層間距離的變化，利用掃描式電子顯微鏡(SEM)觀察層狀石墨烯的厚度，以及利用穿透式電子顯微鏡(TEM)觀察到石墨單層的形貌；接下來由於實驗中使用的石墨烯含有些許的羧酸，使石墨烯能均勻的分散在電活性聚亞醯胺，利用穿透式電子顯微鏡(TEM)進一步觀察石墨分散在電活性聚亞醯胺中之分散形態。石墨烯的添加對其性質研究探討，石墨烯具有較高的視徑比將其成為填充材料，可延長氣體在薄膜中的滲透路徑，減緩金屬表面的鏽蝕速率，以循環伏特電位儀(CV)、交流阻抗模組(Impedance)、氣體透過率分析儀(GPA)得知防蝕效果及阻氣效果提升；由於石墨烯均勻分散在電活性聚亞醯胺中，藉由熱重分析儀(TGA)、示差掃瞄熱卡量計(DSC)、動態機械分析儀(DMA)、熱傳導係數儀(TPS)及介電量測儀(LCR)證明石墨烯的添加使其性質大幅提升。

關鍵字

防腐蝕 ； 聚亞醯胺 ； 電活性 ； 超疏水 ； 石墨烯

並列摘要

In this research, electroactive polyimide (EPI) with amino-capped aniline trimer (ACAT) and 4ʹ-(4,4ʹ-isopropylidene-diphenoxy)bis(phthalic anhydride) (BSAA) as monomers, were prepared by thermal imidization. This study as this electroactive polymer is divided into two parts:
In the first part, nanocasting technique was used to obtain a biomimetic superhydrophobic electroactive polyimide (SEPI) surface structure from a natural Xanthosoma sagittifolium leaf. The superhydrophobic electroactive material could be used as advanced coatings that protect metals against corrosion. The morphology of the surface of the as-synthesized SEPI coating was investigated using scanning electron microscopy (SEM). The surface showed numerous micro mastoids, each decorated with many nano wrinkles. The water contact angle (CA) for the SEPI coating was 155°, which was significantly larger than that for the EPI coating (i.e., CA = 87°). The significant increase in the contact angle indicated that the biomimetic morphology effectively repelled water.
The second part, electroactive polyimide/graphene nanocomposite (EPGN) materials were prepared and then characterized by Fourier-Transformation infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). In-situ monitoring for redox behavior of as-prepared EPGN materials was identified by CV studies. Enhancement of corrosion protection of EPGN coatings on CRS electrode could be interpreted by following three possible reasons: (1) EPI could act as a physical barrier coating. (2) The redox catalytic capabilities of ACAT units existed in EPGN may induce the formation of passive metal oxide layers on CRS electrode, as evidenced by SEM and electron spectroscopy for chemical analysis (ESCA) studies. (3) The well-dispersed graphene nanosheets embedded in EPGN matrix could act as hinder with a relatively higher aspect ratio than clay platelets, which to further effectively enhance the oxygen barrier property of EPGN, as evidenced by gas permeability analyzer (GPA). In addition, effect of material composition on the mechanical, thermal, thermal transport, dielectric and molecular barrier properties of EPGN membranes were also investigated by dynamic mechanical analysis (DMA), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), TPS technique, LCR meter and GPA, respectively. It should be noted that all the properties of EPGN membranes were found to improve substantially than those of non-electroactive polyimide (NEPI) and EPI.

並列關鍵字

graphene ； superhydrophobic ； anticorrosion ； polyimide ； electroactive

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