A complete analysis of plastic additives: the key to performance optimization
What are plastic additives?
Additives are essentially trace compounds added to the basic formula to improve product performance, process efficiency or user experience. In many industrial chains such as chemicals, food, plastics, medicine, and coatings, although the presence of additives is “small in quantity”, it plays a “big in quality” role in performance optimization. In the plastics industry, additives are the key factor in regulating the performance of plastic products.
Functional classification of plastic additives
Mainstream types of function orientation
Plasticizers: used to improve the flexibility of polymers, commonly found in PVC products. For example, when phthalate plasticizers (such as DOP) are added at 30phr, the elongation at break of rigid PVC can be increased from 20% to 350%.
Antioxidants: prevent the oxidation and breakage of polymer chains and extend the service life. Used for PE films and polypropylene containers.
Heat stabilizers: ensure the integrity of the molecular structure during thermal processing. Zinc soap heat stabilizers are particularly effective in rigid PVC.
Flame Retardants: For example, when aluminum hydroxide is added at 60%, the peak heat release rate of PE can be reduced by 52%, and it has passed UL94 V-0 certification (ISO 5660 standard test
UV Stabilizers: Absorb ultraviolet rays, slow down surface fading and cracking, and are commonly used in automotive parts and outdoor furniture.
Synergy and conflict between additives
Some additives have complementary effects. For example, antioxidants and light stabilizers can greatly improve the weather resistance of outdoor products; however, some plasticizers and flame retardants have compatibility issues, which need to be solved by chemical modification or selective substitution.
The impact of plastic additives on the performance of the final product
Tools for adjusting mechanical properties
By selecting different types of additives, the hardness, elasticity and strength of plastics can be precisely controlled. For example, adding 1-2% amino-modified polysiloxane to polycarbonate, the ASTM According to the D3702 test, the friction coefficient can be reduced by 60-70% (from 0.4-0.5 to 0.15-0.2), significantly improving the PV limit value of gear applications
Improving weather resistance and thermal stability
During the plastic processing process, adding appropriate plastic additives can improve the weather resistance and thermal stability of the product, especially under outdoor exposure, high temperature environment or long-term use conditions. The combination of phenolic antioxidants (such as BHT) and phosphate ester synergists can extend the oxidation induction period of polypropylene by 6-9 times and increase the upper limit of the processing window temperature by 15-20°C
Adverse effects of improper use of additives
It should be noted that excessive addition of plasticizers may cause oil seepage on the plastic surface, affecting the appearance and safety of the product; and some heavy metal stabilizer residues may violate environmental regulations and affect export compliance.
How to choose the right plastic additive?
Accurate matching according to the application scenario
Plastics for food packaging: must be selected in accordance with FDA or EU 10/2011 standard food-grade additives, such as citrate plasticizers.
Auto parts: Prefer a combination of additives that are resistant to high temperatures and UV rays, such as brominated flame retardants + antioxidants BHT.
Electrical housing: Flame retardancy and environmental protection must be taken into account, and a halogen-free flame retardant system is recommended.
Conclusion: Choose the right plastic additives to take material performance one step further
Plastic additives ,although only account for a small part of the material, play a key role in performance, stability, and environmental adaptability. Whether it is the production of household plastic containers or the development of aerospace-grade polymer materials, choosing the right combination of additives will greatly affect the competitiveness of the final product. Today, as green transformation and technological innovation continue to accelerate, grasping the development trend of plastic additives means mastering the future dominance of material applications.
