Introduction

Polypropylene (PP) is widely used in power cable insulation due to its excellent electrical insulation properties, thermal stability, and chemical resistance. However, its inherent brittleness and high stiffness limit its broader application, particularly in high-flexibility and impact-resistant cable materials. Researchers have explored various methods to improve PP’s toughness, flexibility, and dielectric properties, among which elastomer modification has emerged as an effective strategy.

This article explores the impact of different elastomers on the mechanical, electrical, and thermal properties of modified PP, providing insights for manufacturers and researchers developing next-generation cable insulation materials.

Why Modify Polypropylene with Elastomers?

Traditional cross-linked polyethylene (XLPE) has been the dominant material for cable insulation, but it has several drawbacks:

• Difficult recyclability: XLPE is a thermoset material that cannot be remelted or reused.
• Production inefficiencies: The cross-linking process requires additional curing and degassing steps.
• Environmental concerns: The disposal of XLPE contributes to pollution.

Polypropylene offers a sustainable alternative due to its recyclability and high temperature resistance (105–110°C). However, PP alone has poor impact resistance and flexibility, necessitating modification with elastomers to enhance toughness, durability, and flexibility.

Experimental Study on Elastomer-Modified PP

To investigate the effect of different elastomers on PP, researchers conducted melt blending experiments with five elastomers:

• CA10A (propylene-based elastomer)
• 2032PM (ethylene-propylene elastomer)
• CA60A (propylene-based elastomer)
• YH-06 (styrene-based elastomer)
• C3080 (ethylene-octene copolymer elastomer)

The study analyzed mechanical properties, dielectric performance, low-temperature impact resistance, and crystalline behavior using advanced testing methods.

Key Findings: How Elastomers Influence PP Properties

1. Mechanical Performance Improvement

Adding elastomers significantly enhances PP’s impact resistance and flexibility, making it more suitable for cable applications.

➡ Key Insights:

• YH-06 provides the best overall flexibility due to its low flexural modulus and high impact resistance.
• 2032PM and C3080 also show significant improvements in flexibility, making them strong contenders.
• CA10A and CA60A offer moderate improvement and are more compatible with high-rigidity applications.

2. Effect on Electrical Properties

Electrical performance is crucial for cable insulation materials, where low dielectric loss and stable dielectric constant ensure efficient power transmission.

➡ Key Insights:

• 2032PM and C3080 significantly degrade PP’s electrical performance, making them unsuitable for high-voltage insulation.
• YH-06 provides the best balance between flexibility and electrical stability.
• CA10A and CA60A maintain acceptable electrical properties, making them viable alternatives.

3. Impact on Polypropylene Crystallization

Elastomer modification affects PP’s crystalline structure, which in turn influences its thermal stability and mechanical performance.

➡ Key Insights:

• Elastomer addition decreases crystallinity, which improves impact resistance but may affect thermal stability.
• 2032PM and YH-06 have the most significant effect on reducing crystallinity, which correlates with their superior toughness.
• CA10A and CA60A show moderate effects, balancing toughness and stability.

Conclusion: Choosing the Right Elastomer for PP Modification

Based on the experimental results, the selection of an appropriate elastomer depends on the desired balance between mechanical strength, flexibility, and electrical performance.

➡ Final Recommendation:

• YH-06 is the best overall modifier, offering both excellent mechanical and electrical properties.
• CA10A and CA60A are well-balanced options, suitable for moderate enhancement.
• 2032PM and C3080 are not recommended for electrical insulation but excel in impact resistance applications.

Future Outlook: Sustainable and High-Performance PP Modifications

With increasing demand for recyclable, high-performance cable materials, research on PP modification with bio-based elastomers and nanocomposite additives is gaining traction. Future work may focus on:

• Enhancing fire retardancy of PP-elastomer blends.
• Exploring bio-based elastomers for sustainable insulation.
• Combining multiple elastomers to optimize both mechanical and electrical performance.

By carefully selecting elastomers, cable manufacturers can develop next-generation polypropylene insulation materials that are durable, flexible, and energy-efficient.

References

1. Yuan, L., Liu, X., Han, X., & Sun, W. (2024). Effect of Different Elastomers on Polypropylene Modification. Wire & Cable, 2024(4), 14-20. DOI: 10.16105/j.dxdl.1672-6901.202404003
2. Gao, Y. et al. (2020). Compatibility Dependent Space Charge Behavior in Polypropylene/Elastomer Blends for HVDC Cables. IEEE Transactions on Dielectrics, 27(3), 947-955.
3. Huang, X. et al. (2020). Material Progress Toward Recyclable Insulation for Power Cables. IEEE Electrical Insulation Magazine, 36(1), 8-18.