Sodium carboxymethyl starch, a seemingly complex chemical term, is actually a very important chemical. It combines the advantages of starch and carboxymethylation technology, exhibiting a series of unique physical and chemical properties. Next, we will delve into the properties, preparation methods, applications, and environmental impact of sodium carboxymethyl starch.

　　Sodium carboxymethyl starch is produced from starch through a carboxymethylation reaction. In this process, the hydroxyl groups on the starch molecule are replaced by carboxymethyl groups, forming carboxymethyl starch. This modification gives sodium carboxymethyl starch better water solubility, stability, and hygroscopicity.

　　As a high-molecular compound, sodium carboxymethyl starch has excellent thickening, suspending, and stabilizing properties. Therefore, in the food industry, it is often used as a thickener, stabilizer, and gelling agent. For example, in foods such as ice cream, jam, and salad dressing, sodium carboxymethyl starch can improve the taste and texture of the product and extend its shelf life.

　　Sodium carboxymethyl starch also plays an important role in the pharmaceutical, textile, and papermaking industries. In the pharmaceutical field, it can be used as an excipient for drugs, such as suspending agents and disintegrants, to help drugs better exert their efficacy. In the textile industry, sodium carboxymethyl starch can be used to prepare printing pastes and sizing agents, improving the quality and performance of textiles. In the papermaking industry, it can be used as a surface sizing agent for paper, improving the strength and water resistance of the paper.

　　Although sodium carboxymethyl starch has many advantages, it may also cause certain environmental problems during production. For example, sodium carboxymethyl starch in wastewater is difficult to degrade and may pollute water bodies. Appropriate environmental protection measures should be taken during production and use to reduce wastewater discharge and minimize environmental impact.

　　In summary, sodium carboxymethyl starch, as an important chemical, has wide applications in various fields such as food, medicine, textiles, and papermaking. By thoroughly understanding its properties, preparation methods, and applications, we can better utilize its advantages while paying attention to its potential environmental problems, contributing to sustainable development.