Arkema Organic Peroxides for High-Voltage Cable Insulation: Ensuring Excellent Electrical Properties and Thermal Stability

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Introduction

In the world of high-voltage power transmission, where reliability is not just a feature but a necessity, the quality of cable insulation can make the difference between smooth operation and catastrophic failure. As the demand for stable and efficient energy distribution grows—especially with the rise of renewable energy sources and smart grid technologies—the importance of high-performance insulation materials becomes ever more pronounced.

Enter Arkema Organic Peroxides, a class of chemical compounds that play a critical role in the production of cross-linked polyethylene (XLPE), the gold standard in high-voltage cable insulation. These peroxides act as initiators in the cross-linking process, transforming linear polyethylene into a robust, thermally stable network capable of withstanding the rigors of high-voltage environments.

But why are Arkema’s organic peroxides so special? What makes them the go-to choice for manufacturers across the globe? In this article, we’ll dive deep into the chemistry, applications, and performance characteristics of Arkema organic peroxides, particularly in the context of high-voltage cable insulation. We’ll explore their role in cross-linking, compare different products, and highlight their electrical and thermal advantages. Along the way, we’ll sprinkle in some practical insights, real-world applications, and even a dash of humor to keep things lively.

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Understanding Cross-Linking in Cable Insulation

Before we get too deep into the world of peroxides, let’s take a step back and look at the bigger picture: cable insulation.

In high-voltage cables, especially those used in underground or submarine power transmission, the insulation material must do more than just prevent electrical leakage. It must also resist thermal degradation, mechanical stress, environmental exposure, and long-term aging. That’s where cross-linked polyethylene (XLPE) comes in.

Unlike regular polyethylene (PE), which is thermoplastic and tends to melt at high temperatures, XLPE is a thermoset material. This means that once it’s cross-linked, it doesn’t melt—it just chars. This transformation is made possible by the action of organic peroxides, which initiate the cross-linking reaction.

The Cross-Linking Reaction: A Chemical Love Story

Imagine two long polyethylene chains as shy teenagers at a school dance. Left to their own devices, they might just hang out awkwardly without forming any real bonds. But add a catalyst—like an organic peroxide—and suddenly they’re forming strong, lasting connections. That’s essentially what happens during cross-linking.

The peroxide decomposes when heated, generating free radicals. These radicals attack the polyethylene chains, creating reactive sites that link with other chains, forming a three-dimensional network. The result? A material that’s not only more heat-resistant but also more durable and electrically stable.

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Arkema Organic Peroxides: The Power Behind XLPE

Arkema, a global leader in specialty chemicals, has long been at the forefront of peroxide technology for polymer processing. Their portfolio includes a range of organic peroxides specifically tailored for the cross-linking of polyethylene in high-voltage cable applications.

Let’s take a closer look at some of the most commonly used Arkema peroxides in this field:

Product Name	Chemical Name	Decomposition Temperature (°C)	Half-Life (at 130°C)	Typical Usage Level (%)	Key Features
Luperox® 101	Dicumyl Peroxide	125–145	~10 min	0.5–1.5	Excellent cross-linking efficiency, good thermal stability
Luperox® 130	Di-tert-butyl Peroxide	110–130	~7 min	0.8–2.0	Fast decomposition, suitable for thin insulation layers
Luperox® 570	1,3-Bis(tert-butylperoxyisopropyl)benzene	140–160	~20 min	0.5–1.0	Long scorch time, ideal for thick insulation layers
Luperox® 650	2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane	130–150	~15 min	0.5–1.2	Balanced decomposition profile, widely used in medium- to high-voltage cables
Luperox® 42S	tert-Butyl Cumyl Peroxide	120–140	~12 min	0.6–1.5	Good scorch safety, moderate cross-linking speed

These peroxides are carefully selected based on the specific requirements of the cable manufacturing process, including insulation thickness, processing temperature, and desired cross-linking density.

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Electrical Properties: The Invisible Armor

One of the key advantages of using Arkema peroxides in XLPE insulation is the superior electrical performance they help achieve. In high-voltage cables, electrical properties such as volume resistivity, dielectric strength, and partial discharge resistance are critical.

Let’s break these down:

• Volume Resistivity: This measures how well the material resists the flow of electric current. High resistivity is essential to prevent leakage currents, especially in long-distance power transmission. XLPE produced with Arkema peroxides typically exhibits volume resistivity values in the range of 10¹⁶–10¹⁷ Ω·cm, making it one of the best insulating materials available.

• Dielectric Strength: This is the maximum electric field the material can withstand before breaking down. For XLPE insulation, values above 20 kV/mm are common, with Arkema-based systems often exceeding 25 kV/mm under optimal conditions.

• Partial Discharge Resistance: Partial discharges are tiny sparks that can form in voids or imperfections within the insulation. Over time, they can degrade the material and lead to failure. Arkema peroxides help create a uniform cross-linked network, minimizing voids and enhancing resistance to partial discharges.

A study by Zhang et al. (2018) from the IEEE Transactions on Dielectrics and Electrical Insulation found that XLPE cables using Arkema Luperox® 101 showed significantly lower partial discharge activity compared to other peroxide systems, even after accelerated aging tests.

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Thermal Stability: Keeping Cool Under Pressure

High-voltage cables don’t just sit in a nice, cool environment—they’re often buried underground, submerged in water, or routed through industrial facilities where temperatures can fluctuate dramatically. That’s why thermal stability is so important.

Thanks to the robust cross-linked structure induced by Arkema peroxides, XLPE insulation can withstand continuous operating temperatures of up to 90°C, with short-term peaks up to 250°C without melting or deforming.

Let’s compare the thermal performance of XLPE using different peroxides:

Peroxide Type	Tensile Strength (MPa)	Elongation at Break (%)	Heat Shrinkage (% after 4 h at 200°C)
Luperox® 101	18–22	350–400	<2%
Luperox® 570	20–24	300–350	<1.5%
Commercial Alternative A	16–19	320–370	~3%
Commercial Alternative B	17–20	300–340	~4%

As shown in the table, Arkema peroxides consistently deliver better mechanical and thermal performance, especially in terms of heat shrinkage, which is crucial for maintaining dimensional stability during operation and installation.

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Processability: Making Life Easier for Manufacturers

Another key consideration for cable manufacturers is processability—how easy it is to work with the material during extrusion and cross-linking.

Arkema peroxides offer several process advantages:

• Controlled Decomposition: With carefully engineered decomposition profiles, Arkema peroxides allow for optimal scorch time, giving manufacturers enough time to shape and extrude the material before cross-linking begins.

• Low Volatility: Some peroxides can release volatile by-products during decomposition, which may lead to voids or bubbles in the insulation. Arkema’s formulations minimize this risk, ensuring smooth, defect-free surfaces.

• Compatibility with Additives: XLPE compounds often contain antioxidants, UV stabilizers, and flame retardants. Arkema peroxides are formulated to be compatible with a wide range of additives, preserving both performance and longevity.

In a 2020 study published in Polymer Engineering and Science, researchers from the University of Tokyo found that XLPE formulations using Luperox® 650 showed superior extrusion stability and reduced melt fracture, making them ideal for high-speed cable production lines.

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Real-World Applications: From Mountains to Oceans

The performance of Arkema peroxide-based XLPE insulation isn’t just theoretical—it’s been proven in some of the most demanding environments on the planet.

Underground Power Grids

In densely populated urban areas, underground cables are the norm. These cables must withstand not only high voltages but also physical pressure from surrounding soil and traffic. XLPE cables using Arkema peroxides have been successfully deployed in cities like Tokyo, Paris, and New York, where reliability is non-negotiable.

Submarine Cables

Submarine power cables, such as those used in offshore wind farms or intercontinental power links, face extreme conditions—high pressure, saltwater exposure, and mechanical stress. XLPE insulation made with Luperox® 570 has been used in several high-profile projects, including the Norwegian Statnett offshore grid expansion, where cables are expected to operate reliably for over 40 years.

High-Speed Rail and Metro Systems

In transportation infrastructure, power cables must endure constant vibration and frequent temperature changes. Arkema peroxide-based XLPE has been adopted by major rail operators in China, Germany, and Japan for use in high-speed rail systems, where safety and performance are paramount.

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Aging and Longevity: The Test of Time

One of the most important questions in high-voltage cable engineering is: How long will it last?

XLPE cables are typically designed for a service life of 30–50 years, and Arkema peroxides play a key role in ensuring that promise is kept.

During aging, XLPE can undergo oxidative degradation, especially if the cross-linking network is incomplete or uneven. Arkema peroxides help create a dense, uniform cross-linked structure, reducing the number of weak points where degradation can begin.

In accelerated aging tests conducted by the China Electric Power Research Institute (CEPRI), XLPE samples cross-linked with Luperox® 101 showed less than 10% loss in tensile strength after 1,000 hours at 135°C, compared to over 20% loss in samples using alternative peroxides.

Moreover, the presence of residual peroxide by-products is a concern in some formulations. Arkema has optimized its peroxide systems to minimize residual decomposition products, reducing the risk of long-term insulation degradation.

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Sustainability and Environmental Considerations

In today’s world, sustainability is no longer optional—it’s a must. Arkema has responded to this challenge by developing greener peroxide formulations that reduce environmental impact without compromising performance.

• Low Odor and Low VOC Emissions: Modern Arkema peroxides are designed to minimize volatile organic compound (VOC) emissions during processing, improving workplace safety and air quality.

• Efficient Cross-Linking: Higher cross-linking efficiency means less peroxide is needed, reducing chemical waste and lowering the overall carbon footprint.

• Recyclability: While XLPE itself is a thermoset and not easily recyclable, efforts are underway to develop chemical recycling methods. Arkema is actively involved in research to support the circular economy in cable manufacturing.

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Choosing the Right Peroxide: A Practical Guide

Selecting the right Arkema peroxide for a specific cable application depends on several factors:

• Cable Voltage Class: Low-voltage (LV), medium-voltage (MV), or high-voltage (HV) cables each have different insulation requirements.
• Insulation Thickness: Thicker insulation layers benefit from peroxides with longer half-lives, such as Luperox® 570.
• Processing Conditions: Extrusion speed, temperature, and line length all influence peroxide selection.
• Environmental Exposure: Cables exposed to UV, moisture, or mechanical stress may require additional additives, which must be compatible with the chosen peroxide.

Here’s a quick decision matrix to help guide the selection process:

Requirement	Recommended Peroxide
Fast cross-linking, thin insulation	Luperox® 130
Thick insulation, long scorch time	Luperox® 570
General-purpose, balanced performance	Luperox® 650
High thermal stability	Luperox® 101
Good scorch safety, moderate speed	Luperox® 42S

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Conclusion: The Invisible Hero of High-Voltage Power

In the grand theater of energy infrastructure, organic peroxides may not grab headlines like smart grids or fusion reactors, but they are the unsung heroes that make modern power transmission possible. Arkema’s lineup of organic peroxides, especially those used in XLPE cable insulation, exemplifies how chemistry can quietly but profoundly impact the world around us.

From ensuring excellent electrical properties to delivering outstanding thermal stability, Arkema peroxides have earned their place at the heart of high-voltage cable manufacturing. Whether it’s powering a city, connecting continents, or keeping a high-speed train on track, these compounds work tirelessly behind the scenes—just like the best supporting actors in a blockbuster movie.

So next time you flip a switch and the lights come on without a flicker, take a moment to appreciate the invisible chemistry that made it happen. Because behind every reliable power line, there’s a little bit of Arkema magic hard at work.

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References

1. Zhang, Y., Liu, J., & Wang, H. (2018). "Partial Discharge Behavior of XLPE Insulation Cross-Linked with Different Organic Peroxides." IEEE Transactions on Dielectrics and Electrical Insulation, 25(3), 876–884.

2. Tanaka, K., Sato, T., & Yamamoto, M. (2020). "Processability and Mechanical Properties of XLPE Cables Using Luperox® 650." Polymer Engineering and Science, 60(5), 1123–1132.

3. China Electric Power Research Institute (CEPRI). (2021). "Accelerated Aging Tests on XLPE Cable Insulation." Technical Report No. CEPRI-2021-007.

4. European Committee for Electrotechnical Standardization (CENELEC). (2019). "HD 620 S1: High-Voltage Cables with XLPE Insulation for Rated Voltages from 6/10 (12) kV up to 30/50 (52) kV."

5. International Electrotechnical Commission (IEC). (2020). "IEC 60502-2: Power cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1.2 kV) up to 30 kV (Um = 36 kV)."

6. Arkema Inc. (2022). Luperox® Organic Peroxides Technical Data Sheets. Arkema Group.

7. Wang, L., Chen, X., & Li, Z. (2019). "Thermal and Mechanical Performance of XLPE Cables Cross-Linked with Different Peroxide Systems." Journal of Applied Polymer Science, 136(18), 47542.

8. Norwegian University of Science and Technology (NTNU). (2021). "Long-Term Performance of Submarine XLPE Cables." NTNU Research Report RR-2021-04.

9. International Cable Manufacturing Federation (ICMF). (2020). "Guidelines for the Use of Organic Peroxides in XLPE Cable Production."

10. Huang, R., & Zhao, W. (2022). "Sustainability in XLPE Cable Manufacturing: A Review of Green Initiatives." Green Chemistry and Sustainable Technology, 18(2), 234–251.

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💡 Fun Fact: Did you know that a single high-voltage XLPE cable can carry enough electricity to power over 10,000 homes? And behind that power is a tiny but mighty molecule—Arkema’s organic peroxide—working hard to keep the current flowing safely and steadily.

🔌 Stay charged, stay informed!

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