1. Plasticizer

Plasticizer can be divided into two categories: primary plasticizer and secondary plasticizer. The characteristics of primary plasticizer are good compatibility with resins, high plasticizing efficiency, migration resistance, low volatility, low oil (water) extraction, and low-temperature flexibility. The solubility of the secondary plasticizer is poor, mainly used together with the main plasticizer to reduce costs, so it is also known as an additive.

2. Antioxidants and light stabilizers

We all know that plastic products undergo aging phenomena such as fading, brittleness, and cracking under the action of light, heat, and oxygen during processing, storage, and use. To delay and prevent the occurrence of aging, stabilizers must be added. Mainly used to prevent thermal aging, it is called a heat stabilizer; Mainly used to prevent oxidative aging, it is called antioxidant; Mainly used to prevent photo aging, they are called light stabilizers, collectively referred to as stabilizers. The best performing plastic stabilizer today is methyl tin heat stabilizer (abbreviated as 181), which is very effective for the rolling, extrusion, injection molding, and blow molding of rigid polyethylene (PVC). Due to its high safety, it is particularly used for food packaging and high-definition hard polyethylene products. At the same time, it is also widely used in plastic doors and windows, water pipes, and decorative materials to replace other highly toxic plastic heat stabilizers. It has been widely used in the United States, Europe, and Japan. In recent years, 181 methyltin heat stabilizers have been widely used in China.

3. Flame retardants

4. Heat stabilizer

The main function of a heat stabilizer is to prevent or alleviate the decomposition of polyvinyl chloride resin during high-temperature plasticization processing, as well as the chemical changes caused by light and oxygen in the environment during the use of the product after molding, thereby changing the performance of the product and shortening its service life. Heat stabilizers inhibit or prevent resin degradation, prolong product lifespan, and have a certain antioxidant effect by absorbing and neutralizing HCl, displacing unstable allyl chloride atoms in PVC molecules, undergoing addition reactions with polyene structures, capturing free radicals, etc., to prevent plastic products from degrading and discoloring. In addition, heat stabilizers can also absorb ultraviolet radiation or shield the resin from damage caused by ultraviolet radiation. When added to mixtures mainly composed of PVC resin, they should not undergo chemical reactions with other additives and should not affect the performance of the product. These mechanisms of action together ensure the important role of heat stabilizers in plastic processing, especially in the processing and application of PVC resin

5. Impact modifier

The main function of impact modifiers is to improve the low-temperature brittleness of polymer materials and endow them with higher toughness. These chemicals play an important role in the field of engineering technology and are widely used in various plastic products, such as PP plastics, PVC resins, etc. Specifically for PVC materials, impact modifiers can increase the hardness and impact resistance of PVC, thereby improving the toughness, strength, and wear resistance of the material, and enhancing the product's service life and performance stability. For example, Acrylic Impact Modifier (AIM) is a high-quality and environmentally friendly plastic modifier mainly used for PVC hard products, such as pipes and fittings, plastic steel doors and windows, panels, containers, etc. AIM disperses particles in the PVC continuous phase matrix, absorbs impact energy when subjected to external forces, prevents the further development of cracks, and thus improves the impact strength of the material. In addition, impact modifiers can also endow PVC products with good processability and weather resistance, making them particularly suitable for outdoor products

6. Foaming agent

As a good foaming agent, it should have the following conditions: release gas in a short period of time, adjustable release rate, inert gases such as CO ₂ and N ₂ released during decomposition, easy dispersion and decomposition in plastics, appropriate decomposition temperature, low heat generation during decomposition, irreversible decomposition reaction, non-toxic foaming agent, etc. The most widely used foaming agent is azodicarbonamide.

7. Coupling agent

Coupling agent refers to a type of substance that can improve the interfacial properties between fillers and polymer materials. There are usually two functional groups in the molecular structure of coupling agents: one can undergo chemical reactions with the polymer matrix or has good compatibility; Another type can form chemical bonds with inorganic fillers. Like; Silane coupling agent, with the general formula RSiX3 (R is an active functional group that has affinity and reactivity with polymer molecules, such as vinyl, chloropropyl, epoxy, methacryloyl, amino, and thiol groups; X is an alkoxy group that can hydrolyze, such as methoxy, ethoxy, etc.). After treatment with a coupling agent, the surface of the reinforcing agent or filler can be chemically modified, forming a bridge bond between the dispersed inorganic phase and the continuous polymer, becoming a composite material that enhances the effect of the reinforcing agent or filler. Organosilane is the most widely used coupling agent, while organic titanate is a more efficient coupling agent.

8. Crosslinking agent

Crosslinking agents are mainly used in polymer materials (rubber and thermosetting resins). Because the molecular structure of polymer materials is linear, without cross-linking, their strength is low, they are easy to break, and they have no elasticity. The role of cross-linking agents is to create chemical bonds between linear molecules, connecting them together to form a network structure, thereby improving the strength and elasticity of rubber. The cross-linking agent used in rubber is mainly sulfur, and accelerators need to be added. Generally, crosslinking agents refer to organic peroxides, such as diisopropylbenzene peroxide, which can be used as a crosslinking agent for polyethylene.

9. Reinforcing materials and fillers

10. Lubricants

11. Release agent

12.Coloring agent

13. Color master batch

14. Antistatic agent

Antistatic agents play a role in eliminating or reducing static electricity generated on the surface of plastic products. Most anti-static agents are electrolytes, which have limited compatibility with synthetic resins. This allows them to migrate to the surface of plastics, achieving the effects of moisture absorption and eliminating static electricity.

15. Antibacterial agents

16. Defoamer

The plastic additive industry in our country has developed with the development of the PVC industry. The proportion of additives in plastic materials is relatively small, but it has a significant impact on the quality of plastic products. High performance green, environmentally friendly, non-toxic, and efficient plastic additives will become the main direction for the development of China's plastic additive industry in the future