评价天然胶在从厄瓜多尔柑橘皮中提取的果胶中作为一种环保型碳钢缓蚀剂的添加效果。

Evaluation of Adding Natural Gum to Pectin Extracted from Ecuadorian Citrus Peels as an Eco-Friendly Corrosion Inhibitor for Carbon Steel.

机构信息

Departamento de Ingeniería Química, Facultad de Ingeniería Química y Agroindustria, Escuela Politécnica Nacional, Ladrón de Guevara, Quito 17-12-866, Ecuador.

Escuela de Ciencias Químicas, Pontificia Universidad Católica del Ecuador, Quito 17-01-2184, Ecuador.

出版信息

Molecules. 2022 Mar 25;27(7):2111. doi: 10.3390/molecules27072111.

DOI:10.3390/molecules27072111

PMID:35408511

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9000655/

Abstract

The production and use of eco-friendly corrosion inhibitors allows valuable compounds contained in plant waste to be identified and repurposed while reducing the use of polluting synthetic substances. Pectin extracted from Tahiti limes () and King mandarin ( L.) in addition to natural gums-xanthan gum and latex from the "lechero" plant ()-were used to create an eco-friendly corrosion inhibitor. The optimal extraction conditions for pectin were determined from different combinations of pH, temperature, and time in a 2 factorial design and evaluated according to the obtained pectin yield. The highest pectin extraction yields (38.10% and 41.20% from King mandarin and lime, respectively) were reached at pH = 1, 85 °C, and 2 h. Extraction of pectic compounds was confirmed using Fourier-transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetry analyses. Subsequently, a simplex-centroid mixture design was applied to determine the formulation of extracted pectin and natural gums that achieved the highest corrosion inhibitor effect (linear polarization and weight loss methods in NACE 1D-196 saline media using API-5LX52 carbon steel). Impedance spectroscopy analysis showed that the addition of xanthan gum to pectin (formulation 50% pectin-50% xanthan gum) improved the corrosion inhibitor effect from 29.20 to 78.21% at 400 ppm due to higher adsorption of inhibitory molecules on the metal surface.

摘要

环保型缓蚀剂的生产和使用可以识别和重新利用植物废料中含有的有价值的化合物，同时减少对污染性合成物质的使用。从塔希提莱檬（Citrus latifolia Tanaka）和皇帝桔（Citrus nobilis Lour.）中提取的果胶以及天然胶-xanthan 胶和“lechero”植物胶乳，被用于开发环保型缓蚀剂。采用 2 因素析因设计，从不同的 pH 值、温度和时间组合中确定果胶的最佳提取条件，并根据获得的果胶产率进行评价。在 pH = 1、85°C 和 2 h 的条件下，果胶的提取率最高（分别为 38.10%和 41.20%，来自皇帝桔和莱檬）。使用傅里叶变换红外光谱、差示扫描量热法和热重分析证实了果胶和果胶化合物的提取。随后，采用单纯形-重心混合设计确定了提取果胶和天然胶的配方，以获得最高的缓蚀剂效果（在 NACE 1D-196 盐水中使用 API-5LX52 碳钢进行线性极化和失重法）。阻抗谱分析表明，由于抑制分子在金属表面的吸附增加，在 400 ppm 时，向果胶中添加 xanthan 胶（配方为 50%果胶-50% xanthan 胶）将缓蚀剂效果从 29.20%提高到 78.21%。