【正文】 ber of ethylene oxide units within the nonionic moiety from 9 to 45 and 68 EO units increases the hydrophilic characters of these molecules, which increases their critical micelle concentrations and also their surface tension values. Increasing of the CMC values can be referred to the formation of hydrogen bonds (HBs) between amphiphiles and water molecules. HBs increase the adsorption of these amphiphiles at the air– water interface, which increases the CMC values gradually. The maximum CMC value was observed for the longest polyethylene oxide chain (n = 68) at mM/L. On the other hand, the effectiveness (π CMC) values of the synthesized Schiff base nonionic amphiphiles SBn 16 were increased gradually by decreasing the length (n) of the nonionic moiety (where n = 9, 45 and 68) [22,23]. The effectiveness (π CMC) and the efficiency (pC20) values showed an increasing trend by increasing the hydrophobic chain length. The maximum lowering in the surface tension values was corresponded to the SB400palmitate. The maximum surface excess (Γ max) values showed lower surface concentration for the Schiff base amphiphiles which have the higher ethylene oxide content. The highest value of the maximum surface excess was observed for SB40016 (Table 2). On contrarily, the minimum surface area (A min) values increased by increasing the nonionic chain lengths, the maximum value of the surface area was observed for SB300016 (Table 2). . 聚環(huán)氧乙烷含量的影響（極性鏈） Fig. 2 表示已合成的非離子型席夫堿的疏水鏈長為常 數(shù)（ 16 亞甲基組）時，環(huán)氧乙烷對表面活性的影響 。最大累積值是 臨界膠束濃度 下的最低表面張力，最大值為 SB2020oleate 的 分子數(shù)在 44 mN/m時的值 。 實驗表明 沒有加緩蝕劑 的 氫氣析出體積為最大值 [19]。 4N HCl 溶液在 25?C 下加入不同濃度范圍 (400– 10 ppm)的緩蝕劑。 16: hexadecanoate 8: octadecanoate and/or oleate) were esterified by the synthesized Schiff base SB in equimolar ratio in xylene as a solvent and ptoluene sulfonic acid (.%) as a dehydrating agent [16]. The reaction was continued until plete removal of the water of the reaction. Vacuum distillation was performed to remove the unreacted materials and the solvent, Scheme 2. The produced nonionic Schiff bases were denoted as SBPEGalkanoate (R) and listed in Table 1. . 非離子型兩性席夫堿的合成 等摩爾比的不同分子量的聚乙二醇（ 400,1000,2020和 /或 3000 ， n= /或 68）和不同鏈長的單鏈烷烴（ R=10：癸酸； 16；棕櫚酸； 18：硬脂酸和 /或油酸）縮合的聚乙二醇酯與已合成的席夫堿在以二甲苯為溶劑，對甲苯磺酸（ .%）做 干燥劑 [16] 的條件下進行酯化反應。 表征 這些化合物對鋁合金緩蝕效率分別采用失重 法 和析氫的技術。選擇緩蝕劑要考慮的兩個因素是：一 ，它 們能夠很方便的由相關原料合成；二， 它們含有帶電子的苯環(huán)或者是有電負性原子，如含有芳香環(huán)的席夫堿 [5,6]。 腐蝕實驗表明合成的非離子型席夫堿是有效的緩蝕劑 。他們的方案也計算了吸附熱力學和這些兩親分子膠束化過程。除去垢之后，金屬可能會受到酸的腐蝕。一些研究機構已經(jīng)開發(fā)了應用于實際的自組裝膜緩蝕劑 [11– 14]。最終產(chǎn)物在 40?C真 空干燥。 . Surface and interfacial tension measurements Surface tension measurements were made for freshly prepared inhibitors solutions in a concentration range of – ?C using a DuNuoy TensiometerKrussK100. Also, interfacial tension measurements were made for inhibitors– oil systems [17]. 測定 表面張力 的測試是用 DuNuoy TensiometerKrussK100 在 25?C 測濃度范圍分布在 –。 緩蝕速率的計算由下面公式計算： Cr (mpy) = KW /ATD 式中， K為常數(shù)， A是面積， T是時間， W是質量損失 mg， D是密度。 這種影響 在 前人 的 著作中已經(jīng) 有 了 解釋 [20,21]，是 由于疏水鏈（非極性相）和水相（極性相） 存在 斥力 ，這種斥力迫使在空氣 /水界面形成分子吸附和在大部分溶液中形成膠束以減小它。最大剩余面積的增加是表示界面分子吸附的增加，因此每個分子的可用區(qū)域減少。緩蝕效果 (πCMC)和緩蝕效率 (pC20)的值說明隨著疏水鏈長度的增加，它們有增多的趨勢。研究兩親分子，吸附和熱力學函數(shù)的計算都基于 Rosen 理論 [24]和 Table 2的表面活性數(shù)據(jù) 。 . Corrosion inhibition efficiency . Effect of alkyl chain length Fig. 3 represents the variation of corrosion inhibition efficiency of the synthesized nonionic Schiff bases amphiphiles containing constant ethylene oxide content (n = 45 EO units). It is clear that the inhibition efficiency increased by increasing the number of repeated methylene groups in the hydrophobic chains. Schiff base polyethylene glycol ABA2020 showed the maximum corrosion inhibition efficiency at %. Comparison between the corrosion rate of the different hydrophobic chains (Fig. 3) showed the following trend: oleate stearate palmitate decanoate. That behavior could be referred for two factors. First, the surface activity of these inhibitors at the interfaces. Second, the longer hydrophobic chains neighbored to each other can easily overlapped. That forms a condensed nonpolar layer consists of the alkyl chains. This layer faced the polar aggressive medium, hence good isolation occurred and the corrosion process stopped. The presence of coiling in these chains (in case of saturated chains) and/or unsaturation sites (in case of oleic acid derivative) enhances the mentioned overlapping. That effect appears obviously in the case of stearate and oleate derivatives (SB202018 and SB2020oleate). Increasing the adsorption tendency (in terms of adsorption free energy, Δ Gads, Table 2) directing the inhibitor molecules towards the metal/corrosive medium interface where the inhibitor molecules act as a barrier。 由烷基鏈形成一個緊密的非極性層。 Figs. 3和 4表明， 兩種技術得到的緩蝕效率有很接近的值而有高度的可比性。這也說明了它們作為緩蝕劑的低效率。緩蝕劑可以合理解釋為膠束和這些緩蝕劑（兩親分子）膠束的形成。這表明低濃度時在金屬 /溶液界面形成了簡單的緩蝕劑膜。 。在較高濃度時η的降低表明，沒有形成連續(xù)的膜是由于在較高濃度時形成了膠束 [19]。 150ppm