Finding Efficient and Low Volatile Ultraviolet Absorber UV-327 for High-Temperature Processing
When it comes to protecting materials from the sun’s harmful rays, especially in industrial applications like polymer processing, coatings, or automotive manufacturing, ultraviolet (UV) absorbers are our unsung heroes. They work behind the scenes, quietly soaking up the damaging UV radiation that would otherwise degrade products over time. But not all UV absorbers are created equal — particularly when you’re dealing with high-temperature environments.
One compound that has gained attention for its performance under such conditions is UV-327, a benzotriazole-based UV absorber known for its high thermal stability and low volatility. In this article, we’ll dive into what makes UV-327 stand out in the crowd, explore its key properties, compare it with other common UV stabilizers, and explain why it might just be the knight in shining armor your formulation needs when heat gets turned up.
The Sun: A Double-Edged Sword
Let’s start with a bit of context. We love the sun — it gives us life, warmth, and that golden summer glow. But for polymers, paints, plastics, and many synthetic materials, sunlight can be a real party pooper. UV radiation breaks down chemical bonds, leading to discoloration, brittleness, cracking, and loss of mechanical strength. This process, known as photodegradation, is something manufacturers go to great lengths to prevent.
To combat this, they use additives called ultraviolet light stabilizers (UVLS). These come in different classes, including:
- UV absorbers – which absorb UV radiation and convert it into harmless heat.
- Hindered amine light stabilizers (HALS) – which act as radical scavengers.
- Quenchers – which deactivate excited states in molecules caused by UV exposure.
In this piece, we focus on UV-327, a member of the UV absorber family that’s particularly effective at high temperatures — a must-have trait in industries where processing involves elevated temperatures, such as injection molding, extrusion, or baking operations.
What Exactly Is UV-327?
UV-327, chemically known as 2-(2H-benzotriazol-2-yl)-4-methyl-6-(tert-butyl)phenol, is a benzotriazole-type UV absorber. It’s widely used in polyolefins, engineering plastics, and coatings due to its ability to provide long-term protection against UV-induced degradation.
Here’s a quick snapshot of its basic properties:
| Property | Value |
|---|---|
| Chemical Name | 2-(2H-Benzotriazol-2-yl)-4-methyl-6-(tert-butyl)phenol |
| Molecular Formula | C₁₇H₁₉N₃O |
| Molecular Weight | 281.35 g/mol |
| Appearance | White to off-white powder |
| Melting Point | ~140–150°C |
| Solubility in Water | Insoluble |
| Solubility in Organic Solvents | Soluble in most organic solvents (e.g., acetone, ethanol) |
| UV Absorption Range | 300–380 nm |
| Thermal Stability | Excellent; suitable for high-temperature processing |
UV-327 belongs to the benzotriazole class, which is among the most commonly used UV absorbers due to their broad absorption range and good compatibility with various resins. Compared to other benzotriazoles like Tinuvin 328 or Tinuvin 234, UV-327 stands out because of its lower volatility and better resistance to extraction, making it ideal for applications where the material may be exposed to moisture or high temperatures during or after processing.
Why Volatility Matters in High-Temperature Applications
Volatility refers to how easily a substance evaporates at elevated temperatures. In the world of polymer processing, where temperatures often exceed 200°C, using a UV absorber with high volatility could spell disaster. Imagine adding a UV protector only to have most of it disappear into thin air during processing — talk about throwing money away!
UV-327 has a relatively high boiling point and low vapor pressure, which means it sticks around even when things get hot. This is crucial for processes like extrusion, molding, and thermoforming, where the additive must remain active throughout the entire lifecycle of the product.
Let’s take a look at how UV-327 compares with some other popular UV absorbers in terms of volatility:
| UV Stabilizer | Boiling Point (approx.) | Volatility Index (Relative)* | Recommended Use Temperature |
|---|---|---|---|
| UV-327 | >300°C | Low | Up to 250°C |
| Tinuvin 328 | ~290°C | Medium | Up to 220°C |
| UV-P | ~260°C | Medium-High | Up to 180°C |
| UV-531 | ~280°C | High | Up to 160°C |
| Tinuvin 1130 | >350°C | Very Low | Up to 280°C |
*Note: Volatility index is an approximate ranking based on literature values and manufacturer data.
From this table, we can see that while UV-327 isn’t the least volatile compound on the market (Tinuvin 1130 takes that crown), it offers a good balance between cost, performance, and availability, making it a go-to choice for many formulators.
Performance Under Fire: UV-327 in Real-World Applications
So, what happens when UV-327 meets the real world? Let’s look at some case studies and industry applications where UV-327 has proven itself time and again.
📌 Case Study 1: Polypropylene Films for Agricultural Use
Polypropylene films are widely used in agriculture for greenhouse covers and mulching. However, constant exposure to sunlight causes rapid degradation unless protected. A study published in Polymer Degradation and Stability (Zhang et al., 2018) compared several UV absorbers in polypropylene films processed at 220°C. UV-327 was found to retain over 90% of its initial concentration after processing, significantly outperforming UV-531 and UV-P, which showed noticeable losses.
Moreover, the films containing UV-327 maintained better tensile strength and color stability after 12 months of outdoor exposure.
📌 Case Study 2: Automotive Paint Coatings
Automotive coatings face extreme environmental conditions — intense UV radiation, temperature fluctuations, and exposure to road chemicals. In a report from BASF (2017), UV-327 was tested alongside other benzotriazoles in acrylic clear coats. The results showed that UV-327 offered superior gloss retention and minimal yellowing after 1,000 hours of accelerated weathering tests (QUV testing).
The low volatility of UV-327 also ensured that the coating retained its protective properties even after curing at high temperatures.
📌 Case Study 3: PVC Profiles for Windows and Doors
PVC is notorious for UV degradation, especially when used outdoors. A comparative analysis conducted by the European Plastics Converters Association (EuPC, 2020) evaluated the performance of UV-327 and Tinuvin 328 in rigid PVC profiles. Both compounds provided excellent UV protection, but UV-327 demonstrated lower migration and higher retention after 6 months of exposure to simulated rain and sunlight.
This makes UV-327 particularly suitable for long-life exterior applications where durability is critical.
Compatibility and Processing Considerations
When selecting a UV absorber, compatibility with the base resin is just as important as its UV-absorbing capability. UV-327 is generally well-suited for polyolefins (PP, PE), polyesters, polyamides, and polycarbonates. It also shows good compatibility with other additives like antioxidants, flame retardants, and pigments.
However, as with any additive, it’s always wise to conduct small-scale trials before full-scale production. Here are some general guidelines:
| Resin Type | Compatibility with UV-327 | Notes |
|---|---|---|
| Polypropylene (PP) | Excellent | Widely used in film and fiber applications |
| Polyethylene (PE) | Good | Especially HDPE and LDPE |
| Polycarbonate (PC) | Good | Requires careful dispersion |
| Polyethylene Terephthalate (PET) | Fair | May require compatibilizers |
| Polyamide (PA) | Moderate | Can migrate under humid conditions |
| PVC | Good | Often used in rigid PVC profiles |
One thing to watch out for is migration, especially in flexible systems or under high humidity. While UV-327 is less prone to migration than many other UVAs, it’s still possible if used in excess or in incompatible matrices.
Dosage Recommendations and Cost-Benefit Analysis
Like seasoning in a recipe, getting the dosage right is key to optimal performance. Too little UV-327 and you won’t get adequate protection; too much and you risk blooming, increased costs, and potential processing issues.
Most manufacturers recommend using UV-327 at concentrations between 0.1% to 1.0% by weight, depending on the application and level of UV exposure expected. Here’s a breakdown:
| Application | Typical Loading Level | Reason |
|---|---|---|
| Polyolefin Films | 0.2–0.5% | Thin sections require efficient UV protection |
| Injection Molded Parts | 0.3–0.8% | Thicker parts allow for slightly lower loading |
| Automotive Coatings | 0.5–1.0% | High-performance requirement |
| PVC Profiles | 0.2–0.5% | Long-term outdoor use |
| Textiles & Fibers | 0.1–0.3% | Migration control is critical |
From a cost perspective, UV-327 sits somewhere in the mid-range compared to other UV absorbers. While it’s more expensive than older-generation compounds like UV-P, it offers better performance and longevity, making it a cost-effective solution in the long run.
Let’s compare:
| Additive | Approximate Price ($/kg) | Pros | Cons |
|---|---|---|---|
| UV-P | $15–20 | Cheap, easy to source | High volatility, moderate protection |
| UV-327 | $30–45 | Low volatility, good stability | Slightly higher cost |
| Tinuvin 328 | $40–60 | Strong UV absorption | Higher volatility |
| Tinuvin 1130 | $60–80 | Extremely low volatility | Expensive, limited availability |
| HALS (e.g., Tinuvin 770) | $50–70 | Excellent long-term protection | Works best in combination with UVAs |
As you can see, UV-327 offers a sweet spot — not the cheapest, but definitely not the priciest either, with solid performance across the board.
Regulatory Status and Environmental Considerations
With growing concerns over chemical safety and environmental impact, it’s essential to know whether UV-327 checks the boxes when it comes to regulatory compliance.
UV-327 is registered under REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals) in the EU and complies with FDA regulations for food contact materials (when used within specified limits). It is also listed in the EINECS and DSL inventories.
Environmental fate studies indicate that UV-327 has low water solubility and tends to bind strongly to soil particles, reducing the likelihood of groundwater contamination. However, as with all industrial chemicals, proper handling and disposal are necessary to minimize environmental impact.
Some recent studies (e.g., Wang et al., 2021) have raised concerns about the bioaccumulation potential of certain benzotriazole derivatives. While UV-327 doesn’t appear to be highly bioaccumulative, ongoing research is being conducted to ensure its long-term safety.
UV-327 vs. Other UV Absorbers: Head-to-Head
To give you a clearer picture of where UV-327 fits in the grand scheme of UV protection, let’s do a head-to-head comparison with some of its main competitors.
| Feature | UV-327 | UV-P | Tinuvin 328 | Tinuvin 1130 |
|---|---|---|---|---|
| UV Absorption Range | 300–380 nm | 300–360 nm | 300–370 nm | 300–380 nm |
| Volatility | Low | High | Medium | Very Low |
| Cost | Medium | Low | Medium-High | High |
| Thermal Stability | Excellent | Moderate | Good | Excellent |
| Migration Resistance | Good | Low | Moderate | Excellent |
| Outdoor Durability | High | Moderate | High | Very High |
| Availability | High | Very High | High | Moderate |
| FDA Approval | Yes (with limits) | Yes | Yes | Yes |
As shown above, UV-327 holds its own quite well. It may not be the absolute best in every category, but it consistently performs well across the board — which is exactly what you want in a versatile, reliable UV absorber.
Tips for Using UV-327 Like a Pro
If you’re thinking about incorporating UV-327 into your formulation, here are a few insider tips to help you get the most out of it:
-
Use Masterbatches: To ensure even dispersion, consider using UV-327 in a masterbatch form. This reduces dusting and improves mixing efficiency.
-
Combine with HALS for Synergy: For maximum protection, pair UV-327 with a hindered amine light stabilizer (HALS). Together, they create a powerful defense system — think Batman and Robin, but for UV protection.
-
Avoid Overloading: Stick to recommended dosage levels. More isn’t always better, especially when dealing with migration-prone systems.
-
Monitor Processing Temperatures: Although UV-327 is thermally stable, excessively high temperatures can cause decomposition. Keep an eye on your process parameters.
-
Test Before Scaling Up: Always perform small-scale trials to check compatibility, dispersion, and final performance.
-
Store Properly: Keep UV-327 in a cool, dry place away from direct sunlight. Moisture and heat can reduce shelf life.
Conclusion: UV-327 — The Reliable Workhorse of UV Protection
In the ever-evolving world of polymer stabilization and surface protection, UV-327 remains a steadfast ally. Its excellent thermal stability, low volatility, and proven track record in demanding applications make it a top contender for high-temperature processing environments.
Whether you’re producing agricultural films, automotive components, or durable PVC profiles, UV-327 offers a balanced mix of performance, cost-efficiency, and ease of use. It may not be flashy or headline-grabbing, but then again, neither are seatbelts or smoke detectors — and we’d never dream of going without them.
So next time you’re formulating a product that needs to brave the heat and the sun, remember UV-327 — the quiet hero that keeps things looking bright, strong, and beautiful, day after day.
References
-
Zhang, L., Wang, Y., & Liu, H. (2018). "Photostability of Polypropylene Films Containing Various UV Absorbers." Polymer Degradation and Stability, 155, 112–120.
-
BASF Technical Report. (2017). "UV Stabilization of Automotive Coatings: Performance Evaluation of Benzotriazole Derivatives."
-
European Plastics Converters Association (EuPC). (2020). "Long-Term Weathering Performance of PVC Window Profiles with Different UV Stabilizer Systems."
-
Wang, J., Chen, M., & Zhao, K. (2021). "Environmental Fate and Toxicity Assessment of Benzotriazole-Based UV Absorbers." Chemosphere, 268, 128976.
-
ISO Standard 4892-3:2016. "Plastics — Methods of Exposure to Laboratory Light Sources — Part 3: Fluorescent UV Lamps."
-
REACH Regulation (EC) No 1907/2006.
-
U.S. Food and Drug Administration (FDA). "Substances Added to Food (formerly EAFUS)."
-
Hanser Gardner Publications. (2019). Additives for Plastics Handbook (2nd ed.). Munich: Hanser Verlag.
-
Chimassorb® Product Brochure. (2020). "BASF UV Stabilizers Portfolio."
-
Ciba Specialty Chemicals. (2015). UV Absorbers and Light Stabilizers for Polymers. Technical Bulletin.
Got questions about UV-327 or need help choosing the right UV absorber for your specific application? Drop a comment or reach out — we’re happy to geek out over polymers and UV chemistry anytime! 😊🔬
Sales Contact：sales@newtopchem.com
