Formic acid is one of the most important raw materials for the production of polyester fibres. In the production of polyester fibres, formic acid can be used as a catalyst or regulator to help control the rate of the polymerisation reaction and the properties of the product. It can promote the esterification reaction and improve the quality and productivity of polyester fibres. For example, in the production of polyester fibres, formic acid can react with terephthalic acid and ethylene glycol to produce polyethylene terephthalate (PET), which is a polyester fibre with high strength, abrasion resistance and good shape retention, and which is widely used in apparel, home textiles and industrial fabrics.
2. Leather processing
In the leather industry, formic acid is a commonly used tanning agent. It can cross-link with the collagen in the leather to make the leather have better flexibility, water resistance and durability. In addition, formic acid can be used in the neutralisation, softening and dyeing of leather. In the neutralisation process, formic acid can neutralise the alkaline substances on the surface of the leather, making the surface of the leather neutral, and creating good conditions for the subsequent processing steps. In the softening process, formic acid can penetrate into the inside of the leather, make the leather fibre loose, so as to improve the softness of the leather.
3. Metal surface treatment
Formic acid also has important applications in the field of metal surface treatment. It can be used as an acid detergent for removing oxidised skin, rust and dirt from metal surfaces. For example, in steel surface treatment, a formic acid solution can chemically react with rust (the main component of which is ferric oxide) on the surface of steel to produce soluble iron ions and carbon dioxide, thus removing the rust. In addition, formic acid can also be used for passivation of metals. By forming a dense oxide film on the metal surface, formic acid can prevent further oxidation and corrosion of the metal.
Second, agricultural applications
1. Feed additives
In animal husbandry, formic acid is often used as a feed additive. It can reduce the pH value of feed, inhibit the growth of harmful microorganisms in feed, and extend the shelf life of feed. For example, adding formic acid to the feed of ruminants (e.g. cattle and sheep) can improve the palatability of the feed and increase the feed intake and digestibility of the animals. In addition, formic acid can also regulate the acid-base balance of animal intestinal tract, promote the growth of beneficial microorganisms and inhibit the reproduction of harmful microorganisms, thus improving the health and production performance of animals.
2. Pesticide intermediates
Formic acid can also be used as pesticide intermediates for the synthesis of a variety of pesticides. For example, certain organophosphorus pesticides require the use of formic acid as a raw material in the synthesis process. These pesticides have efficient insecticidal, bactericidal and herbicidal effects, which can effectively protect crops from pests and diseases and improve crop yield and quality.
Third, the field of medicine and food
1. Pharmaceutical intermediates
In the pharmaceutical industry, formic acid can be used to synthesise a variety of drugs. For example, the synthesis of certain antibiotics, vitamins and hormones requires the use of formic acid as a raw material. In addition, formic acid can be used in the refining and purification process of drugs. It can be used as a solvent or conditioner to help remove impurities from drugs and improve their purity and quality.
2. Food additives
In the food industry, formic acid can be used as a preservative and acidifier. It can inhibit the growth of microorganisms in food and extend the shelf life of food. For example, adding the right amount of formic acid to foods such as beverages, sauces and jams can prevent food from deteriorating and spoiling. In addition, formic acid can also give food a certain sourness and improve the taste and flavour of food.
IV. Other Applications
1. Organic synthesis
Formic acid is an important raw material for organic synthesis. It can be used to synthesise a variety of organic compounds, such as esters, amides and nitriles. For example, through the esterification reaction, formic acid can react with alcohol compounds to produce ester compounds, these ester compounds are widely used in spices, coatings and plastics and other fields.
2. Battery electrolyte
Formic acid can also be used as a component of battery electrolytes. In some fuel cells and lithium-ion batteries, formic acid can be used as a proton donor to participate in electrochemical reactions and improve battery performance and efficiency.
In conclusion, as a multifunctional chemical, formic acid has a wide range of applications in many fields. With the continuous progress of science and technology and the continuous development of new applications, the market demand for formic acid is expected to grow further.