Microwave Desiccation and Stelilization
Microwave is an electromagnetic wave whose frequency ranges from 300MHz to 300GHz. It is a "no temperature gradient" heating mode. Microwave radiation is used for heating reaction, which has the advantages of fast speed, uniform heating, low energy consumption and high efficiency. Microwave radiation does not change the properties of chemical groups substituted on starch. Compared with products obtained by traditional methods, it does not change the chemical structure, particle structure and crystal structure, and it can achieve a higher degree of substitution in a short time.Oxidized starch has been used in paper coating, but there are still some problems such as weak adhesive force. According to the requirements of high solid content of paper coating, starch coating should have both high solid content and high bonding force. Therefore, oxidation and esterification can be combined to reduce the viscosity of starch and esterification to improve the adhesion of starch, so as to obtain low-viscosity and high-strength composite modified starch. The oxidized starch phosphate ester has the common advantages of oxidized starch and starch phosphate ester.
Carboxylic ester is an important organic compound, which can be used not only as raw material for organic synthesis, but also as an important fine chemical product. It is widely used in perfume, daily chemical, food, medicine, rubber, paint and other industries. The traditional synthesis method of this product is based on the corresponding carboxylic acid and alcohol as raw materials and concentrated sulfuric acid as catalyst. This method has many side reactions, complex post-treatment process, serious equipment corrosion, and waste acid emissions polluting the environment. In recent years, scholars at home and abroad have paid special attention to the synthesis of carboxylic esters. They have made breakthroughs in chemical catalysis, physical catalysis, biological catalysis and reaction technology, which greatly improved the yield of esterification and improved the color of products.
Microwave desiccation and stelilization is one of the most important organic chemical reactions. Catalytic esterification technology has always been the focus of chemists'research. While looking for good chemical and biological enzyme catalysts, we should pay close attention to the combination of modern physical catalytic methods and advanced chemical reaction technology to achieve the optimization of the reaction. In addition, the popularization and application of various new technologies in industry is also an important issue urgently needed to be solved by chemical workers.
Microwave desiccation and stelilization, a class of organic chemical reactions, is the reaction of alcohol with carboxylic acid or oxygen-containing inorganic acid to form ester and water. It can be divided into three types: carboxylic acid reaction with alcohol, inorganic oxygenated acid reaction with alcohol and inorganic strong acid reaction with alcohol. The esterification reaction between carboxylic acid and alcohol is reversible, and the reaction is usually very slow, so concentrated sulfuric acid is often used as a catalyst. Polycarboxylic acids react with alcohols to form esters. The reaction of inorganic strong acids with alcohols is generally faster. A typical esterification reaction is the reaction of ethanol and acetic acid to produce ethyl acetate with an aromatic smell. Esterification is widely used in organic synthesis and other fields.