Comparing Light Stabilizer UV-944 with Other Polymeric HALS for the Most Challenging Outdoor Conditions
When it comes to protecting plastics from the relentless sun, not all heroes wear capes — some come in powder or pellet form. In the world of polymer stabilization, light stabilizers are the unsung warriors that keep materials from turning brittle, discolored, and lifeless under the scorching sun. Among these guardians, hindered amine light stabilizers (HALS) have long held the spotlight. But when you’re dealing with the most extreme outdoor environments — think deserts, tropical climates, coastal regions, or even high-altitude zones — not every HALS is created equal.
In this article, we’ll take a deep dive into one of the heavyweights in the polymeric HALS family: UV-944, and compare it head-to-head with other popular polymeric HALS such as Tinuvin 622LD, Chimassorb 944, Tinuvin 144, and LS-292. We’ll look at their performance under harsh conditions, chemical structures, molecular weights, compatibility with various polymers, cost-effectiveness, and more. Think of this as the ultimate showdown between plastic bodyguards — only here, the arena is the great outdoors.
🌞 A Quick Recap: What Are HALS?
Before we jump into the specifics of UV-944, let’s brush up on what HALS actually do. These compounds don’t just block UV light like a sunscreen; they act as radical scavengers. When UV radiation hits a polymer, it generates free radicals — highly reactive molecules that can break down the polymer chain, leading to degradation. HALS intercept these radicals, effectively stopping the degradation process in its tracks.
But not all HALS are built the same. Some are monomeric, meaning they’re smaller molecules with lower molecular weight, while others are polymeric, which tend to offer better durability and resistance to extraction. For long-term outdoor applications, polymeric HALS are often preferred.
🧪 Meet UV-944: The Heavyweight Champion
UV-944, also known as bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, is a high-molecular-weight polymeric HALS. It’s typically used in polyolefins, engineering plastics, and elastomers where long-term weather resistance is critical. Its structure allows it to remain within the polymer matrix longer than lower molecular weight alternatives, making it ideal for extended outdoor exposure.
Key Features of UV-944:
| Property | Value |
|---|---|
| Chemical Name | Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate |
| Molecular Weight | ~1000–1500 g/mol |
| Appearance | White to off-white powder |
| Solubility | Insoluble in water, slightly soluble in organic solvents |
| Typical Loading Level | 0.1–1.0% by weight |
| Thermal Stability | Up to 300°C |
| UV Protection Range | 290–400 nm |
One of the standout features of UV-944 is its excellent resistance to volatilization and migration. This means it stays put in the polymer, even under high temperatures or prolonged UV exposure — a major advantage over some of its competitors.
⚔️ UV-944 vs. the Competition: Let the Battle Begin!
Let’s now pit UV-944 against some of the other well-known polymeric HALS in the market and see how they stack up in real-world performance scenarios.
1. Tinuvin 622LD (BASF)
Tinuvin 622LD is another polymeric HALS based on the same piperidine chemistry. It’s widely used in polyolefins and offers good protection against thermal and photo-oxidative degradation.
| Feature | UV-944 | Tinuvin 622LD |
|---|---|---|
| Molecular Weight | ~1200 g/mol | ~1800 g/mol |
| Volatility | Low | Very low |
| Migration Tendency | Low | Lower than UV-944 |
| Compatibility | Good in polyolefins | Excellent in PE and PP |
| UV Resistance | Strong | Slightly stronger |
| Cost | Moderate | Higher |
While Tinuvin 622LD may have a slight edge in UV protection, UV-944 holds its own, especially in terms of cost and availability. Both are top-tier performers, but if budget is a concern, UV-944 might be the way to go.
2. Chimassorb 944 (BASF)
Yes, Chimassorb 944 sounds eerily similar to UV-944 — and for good reason. They are chemically identical! Chimassorb 944 is essentially the branded version of UV-944 produced by BASF. So why mention it separately? Because sometimes brand matters, and so does supply chain reliability.
| Feature | UV-944 | Chimassorb 944 |
|---|---|---|
| Chemical Identity | Identical | Identical |
| Manufacturer | Generic producers | BASF |
| Availability | Widespread | Regional limitations |
| Price | Lower | Higher |
| Regulatory Approvals | Broad | Extensive (FDA, REACH, etc.) |
If your application requires strict regulatory compliance or you prefer working with a global supplier, Chimassorb 944 might be the better choice. Otherwise, UV-944 is just as effective and more affordable.
3. Tinuvin 144 (BASF)
Tinuvin 144 is a sterically hindered amine with a branched structure that enhances its performance in polyolefins and styrenics.
| Feature | UV-944 | Tinuvin 144 |
|---|---|---|
| Molecular Weight | ~1200 g/mol | ~750 g/mol |
| Volatility | Low | Medium |
| Migration Tendency | Low | Moderate |
| Compatibility | Broad | Best in PP and HDPE |
| UV Resistance | Strong | Slightly lower than UV-944 |
| Cost | Moderate | Higher |
Tinuvin 144 is often chosen for its ease of incorporation and good performance in thin films. However, due to its lower molecular weight, it tends to migrate out of the polymer faster than UV-944, reducing its long-term effectiveness.
4. LS-292 (Songwon / Addivant)
LS-292 is a high-performance polymeric HALS that’s gaining popularity for its exceptional durability.
| Feature | UV-944 | LS-292 |
|---|---|---|
| Molecular Weight | ~1200 g/mol | ~1400 g/mol |
| Volatility | Low | Very low |
| Migration Tendency | Low | Minimal |
| Compatibility | Wide | Narrower (best in PE) |
| UV Resistance | Strong | Comparable |
| Cost | Moderate | High |
LS-292 has shown impressive results in accelerated aging tests and is particularly favored in wire and cable applications. However, its limited compatibility with certain polymers and higher cost make it less versatile than UV-944.
🔥 Real-World Performance: Who Holds Up Under Pressure?
Now that we’ve looked at the specs, let’s get down to brass tacks — how do these stabilizers perform in actual outdoor conditions?
A comparative study conducted by the University of Akron (USA) in 2018 tested the performance of several polymeric HALS in polypropylene samples exposed to QUV accelerated weathering for 2000 hours. Here’s a snapshot of the findings:
| Stabilizer | % Retained Tensile Strength | Color Change (ΔE) | Surface Cracking |
|---|---|---|---|
| UV-944 | 82% | 3.1 | Minor |
| Tinuvin 622LD | 85% | 2.9 | None |
| Chimassorb 944 | 84% | 3.0 | None |
| Tinuvin 144 | 75% | 4.2 | Noticeable |
| LS-292 | 86% | 2.8 | None |
All of these performed admirably, but UV-944 was no slouch. It showed solid retention of mechanical properties and minimal color change — making it a strong contender for applications where aesthetics and strength matter equally.
Another field test conducted in Saudi Arabia (Al-Maktari et al., 2020) evaluated the performance of HALS-stabilized HDPE pipes buried in desert sand under intense sunlight. After 18 months, the pipes treated with UV-944 retained 78% of their original impact strength, compared to 72% for Tinuvin 144 and 81% for LS-292.
🌍 Environmental Factors: Where Does Each HALS Shine?
Different outdoor environments pose unique challenges. Let’s break down how each HALS fares in different climates:
| Environment | Best Performing HALS | Why? |
|---|---|---|
| Desert (High UV + Heat) | UV-944, LS-292 | High MW reduces volatility and migration |
| Tropical (High Humidity + UV) | Tinuvin 622LD | Resistant to hydrolysis and moisture |
| Coastal (Salt Spray + UV) | Chimassorb 944 | Excellent chemical stability |
| Temperate (Moderate UV) | Tinuvin 144 | Cost-effective with acceptable performance |
As you can see, UV-944 is a versatile player across multiple environments, especially where heat and UV are dominant factors. Its balance of performance and price makes it a favorite among compounders and formulators.
💰 Cost Considerations: Can You Afford to Be Picky?
Let’s face it — performance is important, but budgets matter too. Here’s a rough breakdown of current global pricing (as of early 2024):
| HALS | Approximate Price (USD/kg) |
|---|---|
| UV-944 | $5–$8 |
| Chimassorb 944 | $10–$14 |
| Tinuvin 622LD | $12–$16 |
| Tinuvin 144 | $14–$18 |
| LS-292 | $16–$20 |
UV-944 clearly stands out as the most cost-effective option without sacrificing much in terms of performance. If you’re looking to stabilize large volumes of material — say, agricultural films, construction profiles, or automotive parts — UV-944 gives you the best bang for your buck.
🧬 Polymer Compatibility: Does One Size Fit All?
Nope — not quite. While UV-944 works well with a broad range of polymers, its performance can vary depending on the base resin. Here’s a quick guide:
| Polymer Type | UV-944 Performance | Notes |
|---|---|---|
| Polyethylene (PE) | Excellent | Ideal for geomembranes, packaging, and films |
| Polypropylene (PP) | Excellent | Great for automotive parts and textiles |
| PVC | Good | May require co-stabilizers |
| ABS | Moderate | Works but not optimal |
| Polycarbonate (PC) | Fair | Better options available |
| Polyurethane (PU) | Moderate | UV absorbers recommended alongside |
For the most part, UV-944 plays nicely with olefins, which dominate the outdoor plastic market. If you’re working with engineering resins like PC or PU, consider pairing UV-944 with a UV absorber like benzophenone or benzotriazole for enhanced protection.
🧪 Dosage and Processing Tips: Getting the Most Out of UV-944
Using UV-944 effectively requires more than just throwing it into the mix. Here are some best practices:
- Dosage Range: Typically between 0.1% to 1.0%, depending on the severity of the environment and the expected lifespan of the product.
- Processing Temperature: UV-944 is stable up to 300°C, so it can withstand most extrusion and molding processes.
- Compatibility with Antioxidants: UV-944 works synergistically with phosphite antioxidants and phenolic antioxidants. Combining them helps protect against both UV and thermal degradation.
- Avoid Overdosing: Too much of a good thing can lead to blooming or surface migration. Stick to recommended levels unless testing shows otherwise.
📚 References & Literature Cited
Here are some key references that informed this comparison:
- George, G., Joseph, R., & Thomas, S. (2001). Stabilization of polyolefins during processing and weathering. Journal of Applied Polymer Science, 82(1), 1–14.
- Al-Maktari, H. A., Al-Harthi, M. A., & Kamal, M. R. (2020). Outdoor durability of HDPE pipes stabilized with various HALS under desert conditions. Polymer Degradation and Stability, 175, 109104.
- BASF Technical Data Sheet – Chimassorb 944, Tinuvin 622LD, Tinuvin 144 (2023).
- Songwon Industrial Co. – LS-292 Product Bulletin (2022).
- University of Akron Research Report – Accelerated Weathering of Polypropylene Films (2018).
- Scott, G. (Ed.). (1995). Polymer老化 and Stabilisation. Springer Science & Business Media.
✅ Conclusion: UV-944 – The Balanced Performer
So where does that leave us? UV-944 isn’t the flashiest name in the HALS lineup, nor is it always the cheapest or the most powerful. But what it lacks in brand recognition, it more than makes up for in versatility, cost-efficiency, and proven performance under tough conditions.
It’s the stabilizer equivalent of a seasoned utility player — reliable, adaptable, and always ready to step up to the plate. Whether you’re manufacturing agricultural mulch films in Kenya, playground equipment in Arizona, or marine buoys in the Mediterranean, UV-944 has got your back.
Of course, there’s no one-size-fits-all solution in polymer stabilization. Depending on your specific needs — whether it’s regulatory approval, niche polymer compatibility, or ultra-high durability — you might still opt for Tinuvin 622LD, LS-292, or Chimassorb 944. But if you’re looking for a robust, cost-effective, and broadly applicable HALS that thrives in the harshest outdoor environments, UV-944 deserves a prime spot in your formulation toolbox.
After all, in the war against UV degradation, sometimes the quietest soldiers are the ones who hold the line the longest.
Author’s Note:
This article draws from publicly available technical data, peer-reviewed studies, and industry reports. While efforts have been made to ensure accuracy, readers are encouraged to conduct independent testing and validation before finalizing formulations.
Sales Contact：sales@newtopchem.com
