From General to Specialized: How to Choose Additives for High-Temperature Plastics

In large-scale production fields such as aerospace, automotive, and electronics, there are higher demands for a balanced performance in thermal properties, mechanical properties, electrical properties, optical properties, and tribological properties of high-performance components.

Some specialty polymers used in these fields,The peak or long-term heat resistance temperature exceeds 250℃.To achieve optimal performance, these polymers often require the addition of specific additives, which are the materials that help the polymers exhibit excellent performance.

The choice of additives depends on the following two points:

The type of polymer added

Its application scenarios

Reasonable selection of additives helps in developing high-value-added plastics with enhanced durability and other advantages. Additives are particularly crucial for improving the performance of high-temperature polymers.

The three most commonly used additives for high-temperature polymers include:

Flame retardant

Antioxidant

Processing aid

The following will delve into the characteristics brought by each type of additive to high-temperature polymers...

The commonly used commercial flame retardants for high-temperature polymers can be categorized into the following types:

Brominated and chlorinated flame retardants

Phosphorus-based flame retardant

Metal oxide

The material is in general polymers.Most commonly usedFlame retardants, butSome brominated compounds pose health risks.These concerns have prompted the industry to develop halogen-free flame retardants suitable for high-temperature polymers.

There are two types of halogen-free flame retardants that can be effectively applied to high-temperature polymers, namely (Coke type) andMetal oxide(Endothermic type).

Phosphorus-based flame retardantsIncluding organic and inorganic compounds, specifically:

Organophosphate esters

Phosphate

- Halogen-containing phosphorus compounds

Inorganic phosphates

Metal hydroxideIt is the most commonly used halogen-free flame retardant in high-temperature polymers.Aluminium trihydroxideWith low cost and abundant natural resources, it generates alumina through an endothermic reaction, absorbing the heat from the flame. However, the drawback of metal hydroxides is that achieving the desired flame retardant effect in high-temperature polymers requires a high additive amount. A high additive amount can negatively impact the mechanical properties and processing performance of high-temperature polymers.

Other various chemicalsHigh-temperature polymers can also be endowed with flame-retardant properties, includingBoron compounds, melamine, and ammonium sulfamateThe development of novel flame retardant materials for high-temperature polymers is ongoing, including polymer-clay nanocomposites (effective at low additive levels) and silicon-based materials (which can form protective surface coatings during fires and are currently in the research stage).

Flame retardant masterbatchThe formulation is usually customized based on the molecular structure and melt viscosity of the base high-temperature polymer. The selection of flame retardants should be based on the types of flame retardants allowed, the standards that must be met, and the critical mechanical performance requirements of the product. These factors are crucial in determining the optimal flame retardant for a high-temperature polymer.