简述抗氧化剂在塑料中的作用及其选择原则

Quick answer: A practical stabilization strategy starts with the degradation risk first, then screens the additive package around processing conditions, service life, and appearance requirements.

For general plastics stabilization, buyers often compare 抗氧化剂 1010 as a primary phenolic antioxidant with Antioxidant 168 as a phosphite processing stabilizer.

在塑料加工过程中添加适当的抗氧化剂可以阻止或延缓老化过程，从而延长塑料产品的使用寿命。抗氧化剂的选择应根据塑料的类型、加工设备、加工条件、其他添加剂的种类和添加量、产品的使用环境以及产品的使用期限来决定。塑料抗氧化剂的选择基本上应遵循以下原则。

I.兼容性。塑料聚合物与抗氧化剂的相容性往往较差，通常在高温下会将抗氧化剂与聚合物熔融结合，聚合物固化时会将抗氧化剂分子兼容在聚合物分子中间。在配方用量范围内，抗氧化剂要在加工温度下熔化。设计配方时，选用的固体抗氧剂、光稳定剂的熔点或熔融范围的上限，不应高于塑料聚合物的加工温度。

二是迁移。塑料制品，特别是表面积与体积比（或质量比）值较小的制品，氧化作用主要发生在制品表面，这就要求抗氧剂不断从塑料制品向制品表面迁移并发挥作用。但如果向制品表面迁移的速度过快，迁移量过大，抗氧剂就要在环境中挥发到制品表面，或者扩散剂与制品表面其他介质接触而损失，这种损失其实是不可避免的，设计配方时要考虑到。当有选择抗氧剂品种时，应选择分子量相对较大、熔点适当高的品种，并以最严酷的使用环境来确定抗氧剂的使用量。

第三，稳定性。抗氧剂在塑料材料中应保持稳定，在使用环境和高温加工过程中挥发损失小，不变色或变色后不分解（抗氧剂的作用除用于加工过程的热稳定外），不与其他添加剂发生不良化学反应，不腐蚀机械设备，不易被产品表面的其他物质萃取。

第四，加工性。塑料制品加工过程中，加入抗氧剂的树脂粘度和螺杆扭矩可能会发生变化。如果抗氧剂与树脂的熔融范围相差较大，就会产生抗氧剂偏流或抑制螺杆的现象。抗氧剂的熔点低于加工温度100℃以上时，应先将抗氧剂制成一定的母液，再与树脂混合加工产品，以避免因抗氧剂在产品中分布不均而产生偏流和加工成品率下降。

第五，环境与健康。抗氧剂应无毒或低毒，无粉尘或低粉尘，在塑料制品的加工和使用过程中对人体无害，对动植物无害，对空气、土壤和水系无污染。

 

 

A practical selection route for antioxidant, UV absorber, and HALS packages

Most stabilizer decisions work best when they are treated as package decisions rather than single-product decisions. Technical buyers usually get the strongest answer by reviewing long-term heat aging, process stability, weather exposure, and color sensitivity together.

• Separate processing protection from long-term stability: the best additive for melt history is not always the same one that gives the best service-life retention.
• Use synergy deliberately: many polymer and coating systems perform best when primary and secondary stabilizers are paired intentionally.
• Review color and clarity requirements: clear, pale, food-contact, or white systems often need a tighter package than dark industrial products.
• Check the real aging condition: heat, UV, humidity, and outdoor exposure can each change which stabilizer route is commercially strongest.

Recommended product references

• CHLUMIAO 1010: A widely used primary antioxidant benchmark for long-term thermal stability.
• CHLUMIAO 168: A practical process-stability reference when hydroperoxide control matters.
• CHLUMILS UV-123: A strong HALS reference for weatherability-focused screens in coatings and polymers.
• CHLUMILS UV-5151: A practical stabilizer-package reference when broader light-aging protection is needed.

FAQ for buyers and formulators

Why are stabilizer packages often stronger than a single additive?
Because different products can protect different parts of the degradation pathway, so the package often covers more risk than one grade alone.

Does adding more antioxidant or UV stabilizer always improve performance?
Not necessarily. Over-dosing can increase cost and sometimes create side effects, so most systems perform best inside a tested dosage window.