Patterns of the process of starch nitration with nitric acid

Q4 Chemistry

Voprosy Khimii i Khimicheskoi Tekhnologii Pub Date : 2023-03-01 DOI:10.32434/0321-4095-2023-146-1-66-72

V. Lukashov, S. Tishchenko, V. Sereda, A. Artyukhov

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Abstract

The article presents the results of the experimental study on the starch nitration process with aqueous solutions of nitric acid. This nitrating medium has a number of advantages over the nitric and sulfuric acids mixture commonly used in industry, in particular it concerns the chemical stability of resulting starch nitrate. The aim of this work is to establish the dependence of nitration degree of starch on the nitration process parameters, taking into account changes in the chemical composition of its macromolecules. The experimental research method involved the use of ferrous sulfate method to determine the nitration degree of starch and IR-Fourier spectroscopy to analyze the macromolecules chemical composition. The parameters of the nitration process were changed in the following ranges: the mass fraction of water in acid solution of 0 to 35%, the temperature of 3.4 to 800С, the nitration module, as the ratio of the mass of the acid solution to the mass of potato starch of 1 to 40, and the nitration time of 1 to 180 min or 24 h. Based on the experimental results, it was found that the maximum degree of starch nitration is achieved with a water mass fraction in the nitrating solution of about 2%; a further increase in its content leads to a decrease in the starch nitration degree. The increase in the starch nitration degree to the maximum value in this case indicates the nucleophilic mechanism of starch nitration. It is shown that the temperature has a weak effect on the starch nitration degree, and nitrates of oxidized starch are formed under the conditions of high temperature. Increasing the nitration modulus leads to an increase in the starch nitration degree. The effect of nitration time on the starch nitration degree is related to the starch property to dissolve in nitric acid. The initial stage of starch nitration process proceeds at a high rate, which is a consequence of the acid intense penetration into the starch amorphous regions and their dissolution. In the following stages, the nitration process is slowed down due to the acid diffusion into the starch crystalline regions. If nitration is continued, a practically stable value of the nitration degree is achieved in the resulting starch nitrate. The obtained results allow choosing rational conditions for preparation of starch nitrate, which is a powerful explosive.

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淀粉硝酸硝化过程的模式

本文介绍了用硝酸水溶液对淀粉进行硝化的实验研究结果。与工业上常用的硝酸和硫酸混合物相比，这种硝化介质有许多优点，特别是它涉及到所产生的硝酸淀粉的化学稳定性。本工作的目的是建立淀粉的硝化程度对硝化工艺参数的依赖关系，并考虑其大分子化学组成的变化。实验研究方法采用硫酸亚铁法测定淀粉的硝化程度，ir -傅里叶光谱法分析大分子化学组成。硝化过程的参数改变以下范围:水的质量分数在0到35%的酸溶液,3.4的温度至800С,硝化反应模块,如酸溶液的质量比1到40的马铃薯淀粉的质量,和1到180分钟的硝化时间或24 h。根据实验结果,发现淀粉的最大程度实现硝化与水质量分数约2%的硝化的解决方案;其含量越高，淀粉的硝化程度越低。在这种情况下，淀粉的硝化程度增加到最大值，说明淀粉的硝化机理是亲核的。结果表明，温度对淀粉的硝化程度影响不大，氧化淀粉的硝酸盐在高温条件下形成。随着硝化模量的增加，淀粉的硝化程度也随之增加。硝化时间对淀粉硝化程度的影响与淀粉在硝酸中的溶解性能有关。淀粉硝化过程的初始阶段以高速率进行，这是强酸渗透到淀粉无定形区并溶解的结果。在接下来的阶段，由于酸扩散到淀粉结晶区域，硝化过程减慢。如果继续进行硝化作用，所得到的硝酸淀粉的硝化程度实际上可以达到一个稳定的值。所得结果可为强力炸药硝酸淀粉的制备选择合理的工艺条件。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Voprosy Khimii i Khimicheskoi Tekhnologii Chemical Engineering-Chemical Engineering (all)

CiteScore

0.90

自引率

0.00%

发文量

期刊介绍： Voprosy Khimii i Khimicheskoi Tekhnologii (Issues of Chemistry and Chemical Technology) is published bimonthly by the Ukrainian State University of Chemical Technology and accepts Ukrainian- or English language high-quality original articles and reviews concerning various fields of research in chemistry and chemical engineering. Our unusual title “Voprosy khimii i khimicheskoi tekhnologii” originates from the transliterated initial Russian title “Issues of Chemistry and Chemical Technology“. The fact of the matter is that Voprosy khimii i khimicheskoi tekhnologii was founded in 1965 as a scientific journal mainly for Russian-reading and Russian-speaking readership when «the Iron Curtain» existed. Since 1991, after Ukraine declared its independence, our Journal began to publish the articles in Ukrainian and English. Multilingualism is our established tradition. We remember and cherish our traditions, but we follow the latest trends in modern science. Papers that are multidisciplinary or address new or emerging areas of chemistry and chemical engineering are particularly encouraged. Thus, the scope is dynamic. It includes but is not limited to the traditional areas of general, inorganic, organic, analytical, physical chemistry and electrochemistry, as well as all conventional areas of chemical engineering (chemistry of high molecular compounds, technology of inorganic and organic substances, processing of combustible minerals, chemical technology of silicates, processes and apparatus of chemical productions, etc.). The Journal publishes papers dealing with newer interdisciplinary areas such as materials science, nano-science, catalysis, computational and theoretical chemistry, surface phenomenon and colloidal systems, environmental chemistry, green chemistry.