用改良硫酸法从山核桃蒲壳中提取糠醛,运用Box-Behnken中心组合试验设计和响应面优化法研究了反应温度、反应时间、硫酸溶液质量分数对糠醛提取率的影响。采用失重法研究了在盐酸介质中糠醛对冷轧钢的缓蚀性能,通过Van’t Hoff方程和Arrhenius方程计算吸附热和表观活化能,并据此讨论了糠醛的缓蚀机制。最佳提取条件为:反应温度152℃、反应时间2.9h、硫酸质量分数6.9%;在此条件下,糠醛提取率为5.7706mg·g-1。在酸洗时间0~12h,酸洗温度30-50℃,盐酸浓度0.2~1.2mol·L-1,糠醛质量浓度大于0.5g·L-1时,糠醛对冷轧钢的缓蚀率均在90%以上,糠醛在冷轧钢表面的吸附符合校正的Langmuir等温吸附方程,吸附是自发进行的。
Furfural was extracted from hickory hull in modified sulfuric acid solution and optimized by response surface methodology. The effects of reaction temperature, reaction time and sulfuric mass fraction on the furfural yield and the optimum conditions were evaluated by Box-Behnken central composite experimental design and response surface methodology analysis. The inhibition performance and mechanism of furfural for cold rolled steel in HCI solutions were studied by weigh〉loss method. Adsorption heat and apparent activation energy were calculated from Van't Hoff and Arrhenius equations, the mechanism of corrosion inhibition is discussed in detail according to the parameters. The optimum extraction conditions were the reaction temperature of 152 ℃, the reaction time of 2.9 h and the sulfuric mass fraction is 6.9%. Under the optimized conditions, the experimental value of furfural extraction yield was 5. 770 6 mg . g-1. The corrosion efficiency of furfural was over 90% in 0. 4--2. 0 mol . L-1 hydrochloric acid for 0--12 hours at 30--50 ℃, with furfural mass concentration greater than 2 g .L-1. The adsorption of the effective corrosion inhibitor of furfural on cold rolled steel surface was spontaneous and follows the I.angmuir adsorption isotherm equation.