Formulating Durable Stabilization Systems with Optimized Loading Levels of Primary Antioxidant 1035

When it comes to polymer stabilization, the name Primary Antioxidant 1035 (commonly known as Irganox 1035, though we’ll avoid brand names for now) is often whispered like a secret ingredient in the chemistry kitchen. It’s not just another additive; it’s the unsung hero that keeps plastics from aging faster than your grandma’s wedding dress left in the attic.

But here’s the thing: tossing in antioxidants willy-nilly won’t do you any favors. Like seasoning a dish—too little and it’s bland, too much and it tastes like regret. The key lies in formulating durable stabilization systems with optimized loading levels of this antioxidant. And that’s exactly what we’re going to unpack today.

What Is Primary Antioxidant 1035?

Before we dive into the nitty-gritty of formulation, let’s take a moment to appreciate what we’re working with.

Primary Antioxidant 1035 is a thioester-type hindered phenolic antioxidant, typically used in polyolefins such as polyethylene (PE), polypropylene (PP), and thermoplastic polyurethanes (TPU). Its primary role? To scavenge free radicals formed during thermal or UV-induced oxidation, thereby delaying material degradation.

Chemical Profile at a Glance:

Now that we know what we’re dealing with, let’s move on to why it matters.

Why Stabilization Matters

Polymers are everywhere—from your toothbrush to your car dashboard. But left to their own devices, they start to fall apart when exposed to heat, light, oxygen, and moisture. This breakdown is called oxidative degradation, and it leads to:

• Loss of tensile strength
• Discoloration
• Brittleness
• Cracking
• Reduced service life

Enter antioxidants. They act like bodyguards for polymer chains, intercepting rogue radicals before they can cause chaos. Without them, many plastic products would literally crumble under pressure—or sunlight.

And while there are different types of antioxidants—primary, secondary, UV stabilizers—they each play a unique role. Primary Antioxidant 1035 falls into the category of radical scavengers, which means it neutralizes peroxide radicals directly.

The Art of Optimization: Finding the Sweet Spot

You might be thinking, “Well, if antioxidants are so great, why not just add more?” That’s a fair question—and one that plagues formulators worldwide. Overloading a system with antioxidant doesn’t always yield better results. In fact, it can lead to:

• Migration and blooming
• Cost inefficiencies
• Processing issues
• Negative impact on mechanical properties

So how do we find that elusive sweet spot where performance meets economy?

Let’s break it down.

Factors Influencing Optimal Loadings

Several factors influence the ideal concentration of Primary Antioxidant 1035 in a given system:

For instance, polypropylene tends to oxidize more readily than polyethylene, so formulations based on PP often require higher antioxidant concentrations—typically in the range of 0.1% to 0.5% depending on exposure conditions.

Real-World Performance Data

To illustrate this point, let’s look at some data from peer-reviewed studies and industrial trials.

Table 1: Effect of Antioxidant 1035 Loading on Tensile Strength Retention in Polypropylene Films After UV Exposure

From this table, we can see that increasing the antioxidant level beyond 0.30% offers diminishing returns in terms of performance, but increases risk of surface bloom—a white powdery residue that forms on the polymer surface due to additive migration.

Another study by Zhang et al. (2020) evaluated the long-term stability of HDPE pipes using varying levels of Antioxidant 1035. Their findings showed that 0.25% provided optimal resistance to thermal aging over a 10-year simulated period, without compromising processability or aesthetics.

Synergy with Secondary Stabilizers

One of the best-kept secrets in polymer formulation is that Primary Antioxidant 1035 works even better when paired with secondary antioxidants such as phosphites or thioesters. These compounds decompose hydroperoxides before they can generate harmful radicals, complementing the radical-scavenging action of Antioxidant 1035.

A classic example is combining Antioxidant 1035 with Phosphite 626 or Thiosynergist DSTDP. This synergistic blend allows for lower total antioxidant loadings while maintaining or even enhancing performance.

Table 2: Comparative Stability of PP Samples with Different Antioxidant Blends

As shown above, blending allows us to reduce the primary antioxidant load while still achieving high oxidation resistance. This is particularly important in applications where cost and aesthetics are both critical.

Processing Considerations

Formulation isn’t just about mixing chemicals—it’s also about how well those chemicals survive the rigors of processing.

During compounding or extrusion, polymers are subjected to high temperatures and shear forces. If an antioxidant degrades or volatilizes during this phase, its effectiveness drops significantly.

Thankfully, Antioxidant 1035 has decent thermal stability, especially when compared to lighter molecular weight antioxidants. However, care must still be taken in high-temperature processes such as blow molding or injection molding of engineering resins.

Table 3: Volatility Loss of Antioxidant 1035 During Extrusion

This shows that while Antioxidant 1035 holds up reasonably well under standard conditions, excessive heat can eat away at its efficacy. Hence, optimizing processing parameters is just as crucial as optimizing formulation.

Application-Specific Guidelines

Not all polymers are created equal, and neither are their needs. Let’s walk through some common applications and recommended antioxidant levels.

1. Polypropylene Packaging

Used in food packaging, medical films, and consumer goods. Requires FDA compliance and low migration.

• Recommended Level: 0.1–0.2%
• Additives to Pair With: Phosphite 626, UV absorber Tinuvin 328

2. HDPE Pipes for Water Distribution

Long-term durability under buried conditions.

• Recommended Level: 0.2–0.3%
• Additives to Pair With: Thiosynergist DSTDP, HALS 770

3. Automotive Components (PP-based)

Exposure to elevated temperatures and engine fluids.

• Recommended Level: 0.2–0.4%
• Additives to Pair With: Phosphite 168, UV stabilizer Chimassorb 944

4. Outdoor Textiles and Geotextiles

Exposed to UV, moisture, and fluctuating temperatures.

• Recommended Level: 0.2–0.5%
• Additives to Pair With: HALS 3346, UV absorber Uvinul 3039

These recommendations aren’t set in stone—they should be validated with accelerated aging tests tailored to the specific application.

Testing Protocols for Optimization

Optimization isn’t guesswork. It’s science backed by testing. Here are some commonly used methods to evaluate antioxidant performance:

1. Oxidation Induction Time (OIT)

Measures the time it takes for a polymer sample to begin oxidizing under controlled high-temperature oxygen flow. A longer OIT indicates better stabilization.

2. Thermogravimetric Analysis (TGA)

Determines thermal decomposition characteristics. Helps assess antioxidant efficiency in delaying degradation onset.

3. UV Aging Chambers

Simulates outdoor weathering conditions. Used to evaluate long-term performance under cyclic UV exposure and humidity.

4. Mechanical Property Testing

Monitors changes in tensile strength, elongation at break, and impact resistance over time.

5. Migration Testing

Especially important in food contact and medical applications. Determines how much antioxidant migrates to the surface or into surrounding media.

By combining these tests, formulators can fine-tune antioxidant levels to meet both performance and regulatory requirements.

Case Study: Stabilizing Recycled Polypropylene

With sustainability being a hot topic, recycled polymers are gaining traction. But recycled PP often comes with pre-existing oxidation damage, making stabilization even more critical.

In a recent case study conducted by a European compounder, recycled PP was stabilized with 0.3% Antioxidant 1035 and 0.1% Phosphite 168. Compared to untreated samples, the stabilized version showed:

• 40% improvement in elongation retention after 1000 hours of heat aging
• 25% slower yellowing index development
• Better melt flow consistency during reprocessing

This demonstrates that even second-life materials can perform like new with the right stabilization strategy.

Regulatory Compliance and Safety

Antioxidants don’t just have to work—they also have to pass regulatory muster. In food contact applications, for instance, additives must comply with FDA 21 CFR 178.2010 and EU Regulation 10/2011 on plastic materials in contact with food.

Antioxidant 1035 is generally approved for use in food contact applications at levels below 0.6%, although typical usage remains well within that limit. Still, migration testing is highly recommended, especially in sensitive applications like baby bottles or medical tubing.

Cost-Benefit Analysis

Let’s talk numbers. While raw material cost is always a concern, the real value of antioxidants lies in extended product life and reduced failure rates.

A basic cost-benefit analysis reveals that for every $1 spent on antioxidants, manufacturers can save up to $10 in warranty claims, recalls, and customer dissatisfaction. That’s not bad for something that makes up less than 1% of the total formulation.

Moreover, optimized formulations allow for lower additive costs without sacrificing performance, thanks to synergistic blends and careful dosing.

Conclusion: Mastering the Balance

Formulating durable stabilization systems with optimized loading levels of Primary Antioxidant 1035 is part art, part science. It requires understanding the polymer, the environment, and the end-use demands. It also means knowing when to go bold and when to hold back.

Too little, and your product ages before its time. Too much, and you risk blooming, cost overruns, and processing headaches. Just right, and you’ve got a formulation that stands the test of time—chemically speaking, of course 🧪😄.

Remember, the goal isn’t just to make plastic last longer—it’s to ensure it performs reliably, safely, and sustainably across its entire lifecycle. And in that pursuit, Primary Antioxidant 1035 is one of our most powerful allies.

References

1. Smith, J., & Lee, H. (2018). Antioxidant Efficiency in Polyolefins: Mechanisms and Applications. Journal of Applied Polymer Science, 135(12), 46231.
2. Zhang, Y., Wang, L., & Chen, X. (2020). Long-Term Thermal Stability of HDPE Pipes with Various Antioxidant Combinations. Polymer Degradation and Stability, 172, 109011.
3. European Plastics Converters Association. (2019). Guidelines for Stabilization of Recycled Polyolefins.
4. American Chemistry Council. (2021). Best Practices in Polymer Additive Formulation.
5. ISO Standard 11341:2004. Plastics — Accelerated Weathering Using Fluorescent UV Radiation and Condensation.
6. ASTM D3895-17. Standard Test Method for Oxidative-Induction Time of Polyolefins by Differential Scanning Calorimetry.
7. FDA Code of Federal Regulations Title 21, Section 178.2010 – Antioxidants.
8. EU Regulation No 10/2011 on Plastic Materials and Articles Intended to Come into Contact with Food.

If you’re looking to develop a custom stabilization system or optimize your existing formulation, feel free to reach out—we love a good polymer puzzle 😄🧪.

Sales Contact：sales@newtopchem.com