Catalyst refers to a substance that can change the rate of chemical reaction but does not consume in the reaction itself. It can also act on plants and change the growth rate of plants. According to the definition of the International Union of Pure and Applied Chemistry in 1981：Catalyst is a substance that changes the reaction rate but does not change the Gibbs free energy of the general standard of reaction.

It is a stable substance that doesn't change in composition, properties, or quality during a reaction. It acts like a lock and key in the reaction system, being highly selective and specific. Mainly, it reflects in:

1. A catalyst does not catalyze all chemical reactions

 2. Some chemical reactions are not the only catalyst

 3. A chemical reaction has more than one catalyst.

In medicine, auxiliaries are substances used in making drugs, apart from the main active ingredients. They are important in preparing pharmaceuticals. In industry, chemicals are added to improve production, product quality, output, or to enhance the product's unique performance.

Also known as additives. High-dose supplements are a crucial part of the product matrix. They greatly affect the product's appearance, structure, and qualities. However, they are not typically considered as auxiliaries.

Catalysts and Auxiliary Categories

There are various catalysts, such as liquid and solid catalysts based on their state. There are also main and co-catalysts based on their size of action. Additionally, there are polymerization, polycondensation, oxidation, reduction, and other catalysts based on the type of reaction.

The reaction system can be divided into two types of catalysts: homogeneous and heterogeneous. Homogeneous catalysts include acid, alkali, soluble transition metal compounds, and peroxide catalysts. Heterogeneous catalysts include metal catalysts, biocatalysts, nanometer catalysts, and others.

Auxiliaries can be divided into five categories based on their function: synthetic, cross-linking, functional, stability, and process auxiliaries. Auxiliaries can be divided into different types to improve various properties. Some auxiliaries are used to enhance processing properties, like lubricants and stabilizers. Others are used to change mechanical properties, such as plasticizers and toughening agents.

The different types of auxiliaries improve various properties. Some auxiliaries enhance processing properties, like lubricants and stabilizers. Others change mechanical properties, such as plasticizers and toughening agents. Auxiliaries also improve optical properties, like pigments and dyes, and aging properties, like antioxidants and anti-mildew agents.

Additionally, there are auxiliaries that improve surface properties, like antistatic agents and wear resistant agents. Some auxiliaries reduce costs, like diluents, solvents, and fillers. Lastly, there are auxiliaries that improve other properties, like foaming agents and combustion promoters.

Usage of Catalysts and Auxiliary Products

Scientists widely use catalysts, which play an important role in chemical production, experiments, and life activities. Some industrial production, such as winemaking and pharmaceuticals, also require catalysts. So the development power of the catalyst is still considerable.

The additives need to work well with the added resin and stay evenly mixed in it for a long time. When in use, plastic auxiliaries that can promote the function of each other should be selected as far as possible.

In order to use products effectively, they need to be adaptable to processing conditions. Additionally, they should disperse evenly during processing and molding. Furthermore, they should be long-lasting and non-volatile. When using, we should also pay attention to the dosage of auxiliaries.

Most of the auxiliaries are dangerous chemicals, some are flammable and explosive, and some are toxic. New technology has improved auxiliaries' performance requirements, leading to rapid industry growth. This will usher in a new era of technological innovation, increased variety, advanced performance, and environmental friendliness. Modern adhesive additives are now focused on being efficient, functional, refined, specialized, serialized, energy-saving, and environmentally friendly.