Thermally Conductive Polymer Compounds

Introduction

In recent years, the growing demand for effective thermal management in electronic devices, LED lighting systems, and battery technologies has significantly increased the importance of thermally conductive materials. Thermally conductive polymer compounds have emerged as lightweight, flexible, and cost-effective alternatives to traditional metals and ceramics. These materials successfully combine the advantageous properties of polymers—such as design flexibility and low density—with the thermal conductivity capabilities of metals and ceramics.

 

Definition and Structure of Thermally Conductive Polymer Compounds

Thermally conductive polymer compounds are composite materials composed of a polymer matrix mixed with fillers that possess high thermal conductivity. While the polymer matrix itself is typically a thermal insulator with inherently low conductivity, the incorporation of functional fillers—such as carbon nanotubes, graphene, boron nitride, or metals—significantly enhances the material’s heat transfer performance.

 

Classification of Thermal Conductive Fillers

Fillers used in these compounds are generally categorized into three main groups:

• Carbon-based fillers: These include graphite, carbon nanotubes (CNTs), and graphene. They provide excellent thermal conductivity and may also contribute to electrical conductivity, depending on the formulation.
• Ceramic-based fillers: Examples include boron nitride (BN), aluminum nitride (AlN), aluminum oxide (Al₂O₃), and silicon carbide (SiC). These materials offer good thermal conductivity while remaining electrically insulating, making them ideal for applications sensitive to electrical current.
• Metal-based fillers: Such as silver, copper, and aluminum, which provide outstanding thermal and electrical conductivity. However, they typically add more weight and cost to the formulation.

 

 

Commercial Filler Examples

• TIMREX® C-Therm grades from Imerys represent advanced thermal conductivity. Adding 20 wt% of these fillers can achieve an in-plane thermal conductivity of approximately 1 W/m·K, which can be increased to 20 W/m·K or higher with greater filler loading. In addition to improved heat dissipation, these fillers can enhance mechanical strength, abrasion resistance, and barrier properties.
• BORATHERM™ grades from Sibelco are high-performance ceramic fillers offering high thermal conductivity and excellent electrical insulation. These grades are based on spherical alumina and aluminum trihydrate (ATH), ensuring uniform particle distribution and good flowability during processing. A specialized demagnetized ATH version (BORATHERM™ SG-E) is available for applications requiring enhanced dielectric strength.

 

Mechanism of Heat Transfer and Key Factors

According to Percolation Theory, fillers form three-dimensional interconnected networks within the polymer matrix, creating effective pathways for heat conduction. Key factors influencing thermal conductivity include:

• Type and structure of the polymer matrix: Polymers with intrinsically higher thermal conductivity and suitable morphology provide a better foundation for thermal pathways.
• Type, shape, and size of fillers: Nanostructured fillers or those with high aspect ratios (e.g., fibrous or platelet-like) contribute to more efficient and continuous thermal networks.
• Filler loading level: Increasing filler content generally improves conductivity, but must be balanced against processability and mechanical properties.
• Uniform filler dispersion: Achieving even distribution without agglomeration is essential for maintaining consistent and stable thermal performance.

 

Advantages and Challenges

Advantages of thermally conductive polymer compounds include:

• Low weight
• Complex moldability
• Lower manufacturing cost
• Corrosion resistance
• Design flexibility

Key challenges involve:

• Achieving uniform dispersion of fillers
• Balancing thermal, mechanical, and electrical insulation properties
• Controlling microstructure during compounding and processing

Applications

These materials find wide-ranging use in industries such as:

• Electronics: heat sinks, housings
• Automotive: engine parts, lighting systems, EV electronics
• LED lighting: chip heat sinks
• Battery systems
• Aerospace
• Medical devices
• Consumer appliances

 

Parsa Polymer Sharif Products

Parsa Polymer Sharif, leveraging selected base resins and proprietary additives, offers high-performance thermally conductive compounds designed to replace metals in applications like LED heat sinks while maintaining excellent mechanical and processing properties. Two key products include:

• ParsaAmid 63910W

• ParsaAmid 21595W TC HF

These grades are engineered to deliver optimized heat transfer, high mechanical strength, and good processability, making them ideal for temperature-sensitive and thermally demanding applications in electronics, automotive, and LED lighting.

 

Conclusion

Thermally conductive polymer compounds offer an effective combination of thermal, mechanical, and economic benefits, providing innovative solutions for thermal management in advanced industries. Their development is particularly vital for applications such as electric vehicles, miniaturized electronics, and lightweight structures, with strong market growth expected in the coming years.

 

References

1. https://www.specialchem.com/plastics/guide/far-from-static-and-heat-managed-conductive-polymers

2. https://www.radicalmaterials.com/thermally-conductive-polymer-compounds-explained/

3. https://www.plastemart.com/plastic-technical-articles/Thermally-conductive-polymer-compounds-have-good-growth-potential-/1518

4. https://www.avient.com/products/engineered-polymer-formulations/conductive-signal-radiation-shielding-formulations/therma-tech-thermally-conductive-formulations