發(fā)布時(shí)間：2018-04-29 10:11

  本文選題：聚苯胺 + 聚丙烯酸��； 參考：《南京大學(xué)》2015年博士論文

【摘要】：不銹鋼具有高機(jī)械強(qiáng)度和良好的耐腐蝕性,因而被廣泛用于工業(yè)生產(chǎn)及大型工程結(jié)構(gòu)中的骨架材料。但不銹鋼的熱力學(xué)性能不穩(wěn)定,暴露在含氯環(huán)境中容易被腐蝕。當(dāng)它與含氯環(huán)境接觸時(shí),腐蝕反應(yīng)會(huì)在其表面發(fā)生,從而破壞或降低鋼結(jié)構(gòu)的完整性。眾所周知,金屬腐蝕會(huì)導(dǎo)致嚴(yán)重的經(jīng)濟(jì)損失,每年全球?yàn)榇讼娜f億美元。因此,發(fā)展新型、智能并且環(huán)境友好的防腐涂層材料是延長不銹鋼使用壽命,提高其在國際市場上競爭力的重要途徑。為了最大限度減少經(jīng)濟(jì)損失,近年來人們在有機(jī)抑制劑、智能、多功能涂層開發(fā)方面進(jìn)行了深入研究,許多針對不同惡劣環(huán)境中不銹鋼防腐的有效方法被提出。主要包括：(1)使用有機(jī)雜原子作為抑制劑。有機(jī)雜原子被認(rèn)為是保護(hù)不銹鋼免受腐蝕引起性能惡化的重要材料,特別是在酸性介質(zhì)中。作為保護(hù)膜,有機(jī)雜原子吸附在金屬表面上,在酸性介質(zhì)中形成阻礙腐蝕性物質(zhì)與金屬表面接觸的物理屏障。(2)使用能夠持久抗腐蝕保護(hù)的有機(jī)涂層。其中,以導(dǎo)電聚合物為基礎(chǔ)的“智能”復(fù)合涂層,即使金屬表面存在缺陷的區(qū)域暴露于腐蝕環(huán)境中也能有效防止腐蝕。聚苯胺被認(rèn)為是導(dǎo)電聚合物中最好的防腐蝕材料,因?yàn)樗梢源嬖谟诓煌臓顟B(tài)下(氧化/還原狀態(tài)),并且在適當(dāng)條件下,這些狀態(tài)之間很容易相互轉(zhuǎn)換,聚苯胺經(jīng)歷氧化還原過程后在金屬表面誘導(dǎo)形成鈍化氧化層。然而,聚苯胺在水溶液中非常差的溶解性限制了其在涂層材料和腐蝕抑制劑中的應(yīng)用。(3)使用功能性有機(jī)涂層�！爸悄堋蓖苛系母拍钜驯粦�(yīng)用于功能性涂料,例如,功能性涂層具有針對內(nèi)在或外在事件能產(chǎn)生某種刺激響應(yīng)的自修復(fù)能力。這一自修復(fù)能力可通過釋放包裹在納米反應(yīng)器中的修復(fù)劑來實(shí)現(xiàn)。為了避免添加的修復(fù)劑在反應(yīng)體系中可控釋放困難的問題,自身有自修復(fù)能力的材料表現(xiàn)出很好的優(yōu)勢。然而,自修復(fù)機(jī)理目前尚不清楚,利用聚電解質(zhì)自組裝膜對一些嚴(yán)重?fù)p傷進(jìn)行自修復(fù)仍具有一定的挑戰(zhàn)性。設(shè)計(jì)組裝多層結(jié)構(gòu)可以將智能和功能性有機(jī)涂層相結(jié)合,通過一些常用的方法就能夠?qū)崿F(xiàn),如噴涂、浸漬和旋涂。其中,浸漬和旋涂可以精確控制涂層的組成和厚度,通過浸漬涂布和使用層疊技術(shù)制備聚電解質(zhì)自組裝的納米網(wǎng)絡(luò);旋涂也是一種容易和可靠的方法,但由于涂層的形態(tài)受溶劑類型、濃度和濕度的顯著影響,造成涂層耐腐蝕性的可控性降低。基于以上討論,利用可加工的聚苯胺復(fù)合物為抑制劑,以及組裝成多層結(jié)構(gòu)是一種提高涂層在侵蝕性環(huán)境下保護(hù)能力的理想途徑。此外,涂層的制備參數(shù),例如溶液濃度(c)和盤旋轉(zhuǎn)速度(ω),電解液的擴(kuò)散行為和浸漬溶液的pH值等,都會(huì)在多層組裝過程中影響涂層的厚度和耐腐蝕性。因此,通過在調(diào)整工藝參數(shù),開發(fā)智能、具有自修復(fù)和氧化還原催化性能的防腐涂料,是不銹鋼防腐領(lǐng)域中的研究重點(diǎn)。本工作的目的是采用以上所述的這三種策略,得到智能的防腐效果,實(shí)現(xiàn)在不同環(huán)境中保護(hù)不銹鋼。本論文中,我們采用一步原位聚合法制備了具有優(yōu)異的加工性和導(dǎo)電性的水溶性聚苯胺-聚丙烯酸(PANI-PAA)復(fù)合材料。并研究了這些復(fù)合材料在強(qiáng)酸性介質(zhì)中對316不銹鋼的防腐保護(hù)性能。然后,我們采用旋涂法裝制備了聚苯胺-PAA/PEI多層結(jié)構(gòu)的復(fù)合材料,研究了層數(shù)對聚苯胺-PAA/PEI防腐蝕性能的影響,并優(yōu)化了防腐蝕保護(hù)性能。在旋涂組裝期間,優(yōu)化了諸如c和ω等因素,獲得了厚度可控的多層結(jié)構(gòu)。基于對多層結(jié)構(gòu)內(nèi)擴(kuò)散行為的系統(tǒng)研究,探討了耐腐蝕性增強(qiáng)的機(jī)理。此外,我們還研究了PDDA/PAA多層涂層的應(yīng)激自修復(fù)行為。研究工作主要包括如下幾個(gè)方面：(1)水溶性PANI-PAA復(fù)合物的制備。通過在絕緣基質(zhì)(如PAA)中進(jìn)行苯胺單體的聚合,可顯著提高PANI的水溶性。PAA作為基質(zhì)不僅提高聚苯胺在水中的溶解度,而且還防止聚苯胺團(tuán)聚體的形成。抑制劑在316SS表面的吸附過程滿足Langmuir吸附等溫線,在優(yōu)化PAA濃度為200 ppm條件下制得的PANI-PAA的抑制效率最佳。防腐性的提高是由于PANI-PAA吸附形成的絕緣界面層抑制了界面處的腐蝕反應(yīng)。(2)采用交替沉積法制備多層結(jié)構(gòu)的聚苯胺-聚丙烯酸／聚乙烯亞胺(PANI-PAA/PEI)復(fù)合涂層。旋涂過程中加熱有助于殘留水分的去除,這使得多層膜的厚度與層數(shù)量(n)呈線性增加的關(guān)系。PANI-PAA復(fù)合物與PEI的結(jié)合以及多層結(jié)構(gòu)實(shí)現(xiàn)了對316不銹鋼耐腐蝕性的協(xié)同增強(qiáng)。有趣的是,PANI-PAA/PEI涂層的防腐蝕保護(hù)性能在n=20時(shí)最佳。我們認(rèn)為：這應(yīng)歸因于界面氧化物層的形成,以及多層結(jié)構(gòu)延長了腐蝕性離子的擴(kuò)散路徑。(3)制備了厚度在0.47至2.94微米范圍內(nèi)可調(diào)的PANI-PAA/PEI涂層。由于具有電活性與氧化還原催化能力,使得涂層的防腐蝕保護(hù)效率大幅提高。該涂層后在3.5%NaCl溶液中浸泡120小時(shí)仍穩(wěn)定,電解質(zhì)在涂層內(nèi)的擴(kuò)散行為是時(shí)間的函數(shù)�；谙到y(tǒng)研究,我們提出了涂層對電解液在多層結(jié)構(gòu)內(nèi)擴(kuò)散行為產(chǎn)生影響的機(jī)制。(4)制備了具有顯著刺激響應(yīng)性自修復(fù)和抗腐蝕能力的聚二甲基二氯(PDDA)／聚丙烯酸(PAA)多層涂層材料。采用層疊(LBL)技術(shù),我們能夠?qū)訑?shù)(n)和涂層厚度進(jìn)行精確控制。研究了該涂層針對430不銹鋼的防腐性能,以及涂層自修復(fù)性能對層數(shù)的依賴性。結(jié)果表明,自修復(fù)歸因于刺激響應(yīng)腫脹和聚電解質(zhì)多層膜在劃痕附近的靜電修復(fù)�？垢g能力的提高主要是由于多層結(jié)構(gòu)的自修復(fù)功能及其延長并阻礙了腐蝕性物質(zhì)的擴(kuò)散通路。
[Abstract]:Stainless steel has high mechanical strength and good corrosion resistance, so it is widely used in industrial production and skeleton materials in large engineering structures. However, the thermodynamic properties of stainless steel are unstable and exposed to corrosion in the chlorine containing environment. When it contact with the chlorine containing environment, the corrosion should occur on its surface, thereby destroying or reducing steel. It is well known that metal corrosion will lead to serious economic losses and consume trillions of dollars a year worldwide. Therefore, the development of new, intelligent and environmentally friendly anticorrosive coating materials is an important way to prolong the service life of stainless steel and to improve its competitiveness in the international market. To minimize economic losses, In recent years, people have studied the development of organic inhibitors, intelligent and multifunctional coatings. Many effective methods for stainless steel corrosion in different harsh environments have been proposed. (1) the use of organic hetero atoms as inhibitors is considered to be important to protect stainless steel from corrosion. Material, especially in acid medium. As protective film, organic heteroatoms adsorb on metal surfaces, form a physical barrier that impede contact between corrosive substances and metal surfaces in acid medium. (2) use an organic coating that can endure corrosion protection. Areas with defective surfaces can also be exposed to corrosion in a corrosive environment. Polyaniline is considered to be the best anticorrosion material in conductive polymers, because it can exist in different states (oxidation / reduction state), and under appropriate conditions, these states are easily converted to each other, and polyaniline is redox through oxidation and reduction. Passivating oxidation layer is induced on the surface of metal. However, the very poor solubility of Polyaniline in aqueous solution restricts its application in coating materials and corrosion inhibitors. (3) the use of functional organic coatings. The concept of "intelligent" coatings has been applied to functional coatings, for example, functional coatings are intrinsic or external. The self repair capability of an event can produce some kind of stimulus response. This self repair ability can be achieved by releasing a reparative agent wrapped in a nano reactor. In order to avoid the problem that the added restorant can release the difficult problem in the reaction system, the self repairing material has a good advantage. However, the self repair mechanism is present. It is not clear that the use of polyelectrolyte self assembly membranes is still challenging to self repair some serious damage. The design and assembly of multilayer structures can be combined with intelligent and functional organic coatings, such as spraying, impregnation and spin coating, in which impregnation and spin coating can be used to control the coating accurately. The composition and thickness of Nanonetworks with self assembly of polyelectrolyte are prepared by impregnation coating and stacking technology; spin coating is also an easy and reliable method, but because the morphology of the coating is affected by the type of solvent, concentration and humidity, the controllability of the corrosion resistance of the coating is reduced. Based on the above discussion, the machinable polyphenylene is used. In addition, the preparation parameters of the coating, such as solution concentration (c) and disk rotation speed (omega), the diffusion behavior of the electrolyte and the pH value of the impregnated solution, will affect the thickness of the coating during the multi-layer assembly process. Therefore, by adjusting the process parameters, developing the intelligent anticorrosion coatings with self repairing and redox catalytic properties, it is the focus of research in the field of stainless steel anticorrosion. The purpose of this work is to use the above three strategies to obtain the antiseptic effect of intelligent corrosion protection and to realize the protection of stainless steel in different environments. In this paper, we have prepared a water-soluble polyaniline polyacrylic acid (PANI-PAA) composite with excellent machinability and conductivity by one step in situ polymerization, and studied the anticorrosion and protection properties of these composites on 316 stainless steel in strong acidic medium. Then, we have prepared the polyaniline -PAA/PEI multilayer structure by using the spin coating method. The influence of the number of layers on the corrosion resistance of polyaniline -PAA/PEI was studied and the corrosion protection performance was optimized. During the spin coating assembly, the factors such as C and Omega were optimized, and the thickness controlled multilayer structure was obtained. Based on the systematic study of the diffusion behavior in the multilayer structure, the mechanism of corrosion resistance enhancement was discussed. In addition, I The stress self repair behavior of PDDA/PAA multilayer coatings is also studied. The research work mainly includes the following aspects: (1) preparation of water-soluble PANI-PAA complexes. By polymerization of aniline monomers in the insulating matrix (such as PAA), the water-soluble.PAA of PANI can be significantly increased as the matrix not only to increase the solubility of Polyaniline in water, but also to improve the solubility of Polyaniline in water. The formation of polyaniline aggregates is also prevented. The adsorption process of the inhibitor on the surface of the 316SS satisfies the Langmuir adsorption isotherm, and the inhibition efficiency of the PANI-PAA obtained by optimizing the PAA concentration of 200 ppm is the best. The anticorrosion is due to the corrosion reaction under the interface layer of the insulating interface formed by PANI-PAA adsorption. (2) the use of alternation. Polyaniline polyacrylic acid / polyethyleneimine (PANI-PAA/PEI) composite coating has been prepared by deposition. During the process of spin coating, heating helps to remove the residual moisture. This makes the thickness of the multilayer film increasing linearly with the number of layers (n). The bonding of the.PANI-PAA complex with the PEI and the corrosion resistance of the 316 stainless steel to the multilayer structure It is interesting that the anticorrosion protection performance of the PANI-PAA/PEI coating is best at n=20. We think that this should be attributed to the formation of the oxide layer of the interface and the extension of the diffusion path of the corrosive ions by the multilayer structure. (3) the PANI-PAA/PEI coating with adjustable thickness in the range of 0.47 to 2.94 microns is prepared. The anti-corrosion protection efficiency of the coating is greatly improved by the catalytic activity and redox catalytic ability. After the coating is soaked in 3.5%NaCl solution for 120 hours, the diffusion behavior of the electrolyte in the coating is a function of the time. Based on the system study, we put forward the mechanism that the coating affects the diffusion behavior of the electrolyte in the multilayer structure. (4) a polymethyl two chloride (PDDA) / polyacrylic acid (PAA) multilayer coating material with significant response to self repair and corrosion resistance is prepared. Using LBL technology, we can accurately control the layer number (n) and coating thickness. The corrosion resistance of the coating to 430 stainless steel and the self repair performance of the coating to the layer are studied. The results show that the self repair is attributable to the swelling of the stimulus response and the electrostatic repair near the scratch of the polyelectrolyte multilayer film. The improvement of corrosion resistance is mainly due to the self repair function of the multilayer structure and its extension and hindering the diffusion pathway of the corrosive substances.

【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：TG174.4

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相關(guān)期刊論文 前2條

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本文編號：1819486