Plastics Industry

Release time：2025-09-24 10:56:35

As an important pillar of modern materials industry, the development of the plastic industry cannot be separated from the support of various chemical products. From basic resin raw materials to functional additives, chemicals run through the entire process of plastic production and processing, determining the final performance and application areas of plastic products. The application of chemicals in the processing of different types of plastics
The performance of plastic products depends not only on the type of base resin, but also closely related to the added chemicals and their processing technology. Due to the differences in molecular structure and performance characteristics of different types of plastics, specific chemical combinations need to be added in a targeted manner to meet the needs of various application scenarios. From general plastics to engineering plastics, from hard products to soft films, the precise application of chemicals has shaped the diversified product system of modern plastic industry.
The application of chemicals in polyvinyl chloride (PVC) products. As a multifunctional plastic, PVCs processing and application rely heavily on various specialized chemicals. Pure PVC resin is prone to thermal degradation at high temperatures, releasing hydrogen chloride gas, leading to material discoloration and performance degradation. Therefore, heat stabilizers are essential in PVC processing. Traditionally, lead salt stabilizers have been used, but due to environmental and health considerations, lead-free stabilizers such as calcium zinc (Ca/Zn) composite stabilizers have gradually become mainstream choices, especially in the field of building materials such as PVC pipes. Plasticizers are a key component of soft PVC products, with an addition amount of up to 30% -50% of the resin weight. Phthalate plasticizers such as di (2-ethylhexyl) phthalate (DEHP) have long dominated the PVC plasticizer market due to their excellent performance and cost-effectiveness, and are widely used in medical catheters, wires and cables, and other fields. However, due to health hazards, regions such as Europe and America have gradually restricted the application of certain phthalates in sensitive fields, promoting the development of new plasticizers such as citrate esters and polyesters.  
  PVC processing also requires the assistance of lubricants, as PVC melt has high viscosity and poor fluidity, which can easily lead to processing difficulties. Proper addition of lubricants can improve melt flowability, reduce processing temperature, and increase production efficiency. According to different mechanisms of action, PVC lubricants are divided into internal lubricants (such as stearic acid) and external lubricants (such as PE wax), which together ensure the smooth flow of PVC melt during extrusion or injection molding without adhering to equipment. In the formulation design of PVC pipes, the use of fillers (such as calcium carbonate) should also be considered to reduce costs, while adding appropriate amounts of impact modifiers (such as CPE, MBS) to improve the low-temperature toughness of the pipes and meet the requirements of building materials standards.
Optimization of Chemicals in Polyolefin (PE/PP) Products: Polyethylene (PE) and polypropylene (PP), as the most abundant polyolefin plastics, cannot be processed and applied without the combination of various functional chemicals. Polyolefins are prone to oxidative degradation during processing and use, therefore antioxidant systems are crucial. A typical formula includes a synergistic combination of primary antioxidants (such as hindered phenolic compound β - (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecanol ester) and auxiliary antioxidants (such as triphosphate (2,4-di-tert-butylphenyl) ester), effectively capturing free radicals and decomposing peroxides, extending the service life of the product. For PE products that require outdoor use such as agricultural film, light stabilizers such as hindered amines (HALS) need to be added to resist the destructive effects of ultraviolet rays in sunlight, significantly extending the service life of the film.  
  The transparency of PP plastic is usually poor, and adding nucleating agents can promote PP crystallization refinement, improve its transparency and surface gloss. Sorbitol derivatives are highly efficient PP nucleating agents that can achieve a transparent effect similar to polystyrene in PP products, and are widely used in food packaging and medical devices. PP is also prone to static electricity accumulation. Adding anti-static agents such as glycerol monostearate can reduce surface resistance and prevent dust adsorption, which is particularly important in electronic product packaging. For PP parts used in automobiles, it is usually necessary to add fillers such as talcum powder to improve rigidity and heat resistance, while also using elastic toughening agents to improve low-temperature impact resistance and meet the stringent requirements of automotive environments.
Engineering plastics and high-performance additives. Engineering plastics such as ABS, PC, PET, etc. have stricter requirements for additives and need to maintain stable performance under harsh conditions such as high temperature and high stress. Due to the presence of butadiene components, ABS plastic has relatively poor weather resistance and is prone to yellowing and brittleness during outdoor use. Therefore, efficient UV absorbers such as benzotriazole compounds need to be added in combination with antioxidants to significantly improve the durability of ABS in applications such as automotive and electronic casings. Although PC plastic has excellent impact resistance, it is prone to hydrolysis during processing and must undergo strict drying, sometimes requiring the addition of hydrolysis stabilizers; Meanwhile, the scratch resistance of PC is limited, and adding appropriate scratch resistant agents such as silicone compounds can improve its surface properties, making it suitable for high-end applications such as eyeglass lenses and electronic displays.  
  PET plastic dominates in the fields of beverage bottles and fibers, and its processing requires controlling the crystallization rate. Adding appropriate nucleating agents can regulate the crystallization behavior of PET, improve the formability of bottle preforms, and ultimately enhance the transparency of the bottle. For flame-retardant engineering plastics such as flame-retardant ABS, flame-retardant PC, etc., efficient flame retardant systems such as bromine antimony synergistic systems or phosphorus based flame retardants need to be added to meet the strict fire protection requirements of electronic and electrical products. The application of coupling agents (such as silane coupling agents) is crucial in fiberglass reinforced engineering plastics, as it can improve the interfacial bonding between fiberglass and resin matrix, significantly enhancing the mechanical strength of composite materials.  
Table: Key Additives and Their Functions for Major Plastic Types;