comparing uv absorber uv-0 with other basic uv screening agents
comparing uv absorber uv-0 with other basic uv screening agents
when it comes to protecting materials from the harmful effects of ultraviolet (uv) radiation, uv absorbers are like the unsung heroes of polymer science and coatings technology. among them, uv-0, also known as 2-hydroxy-4-methoxybenzophenone, stands out for its versatility and effectiveness. but how does it really stack up against other basic uv screening agents?
in this article, we’ll take a deep dive into uv-0 and compare it with several commonly used uv stabilizers — including uv-9, uv-531, uv-327, and benzotriazole-based compounds like uv-p and uv-326. we’ll explore their chemical structures, absorption spectra, solubility, thermal stability, compatibility with different resins, cost, and regulatory status. and yes, there will be tables — because who doesn’t love a good table?
1. a brief introduction to uv absorbers
before jumping into comparisons, let’s quickly recap what uv absorbers do.
uv absorbers work by absorbing uv radiation and converting it into harmless heat energy before it can cause damage to polymers, coatings, or other sensitive materials. without these additives, sunlight can cause degradation, yellowing, cracking, and loss of mechanical properties — not exactly what you want in outdoor products.
there are several families of uv absorbers:
- benzophenones (e.g., uv-0, uv-9)
- benzotriazoles (e.g., uv-p, uv-326)
- triazines (used mainly as secondary stabilizers)
- hindered amine light stabilizers (hals) (though they work differently)
each has its strengths and weaknesses. our focus here is on comparing uv-0 with some of the most widely used members from each category.
2. meet uv-0: the benzophenone veteran
uv-0, chemically known as 2-hydroxy-4-methoxybenzophenone, is one of the oldest and most studied uv absorbers. it belongs to the benzophenone family, which is known for broad-spectrum uv absorption, especially in the uv-a range (320–400 nm).
key features of uv-0:
- absorption range: 280–380 nm
- peak absorption: ~330 nm
- solubility: soluble in organic solvents; limited in water
- compatibility: good with many resins (especially pvc, polyurethane, and acrylics)
- stability: moderate thermal stability; may volatilize at high processing temperatures
- cost: relatively low
- regulatory status: generally accepted in industrial applications; restricted in food contact materials in some regions
3. uv-0 vs. uv-9: the benzophenone shown
let’s start with another benzophenone: uv-9, or 2-hydroxy-4-n-octoxybenzophenone. it’s often compared to uv-0 due to structural similarities.
| property | uv-0 | uv-9 |
|---|---|---|
| chemical structure | methoxy group | octoxy group |
| molecular weight | 224.24 g/mol | 306.37 g/mol |
| absorption range | 280–380 nm | 300–400 nm |
| peak wavelength | ~330 nm | ~345 nm |
| solubility in water | very low | practically insoluble |
| oil solubility | moderate | high |
| compatibility | good with polar resins | better in non-polar systems |
| cost | low | slightly higher than uv-0 |
what does this mean?
uv-9 has a longer alkyl chain (octoxy), which improves its solubility in oils and non-polar systems like polyolefins. its absorption spectrum shifts slightly toward the visible range, making it effective for films and coatings that need protection under prolonged sunlight exposure.
however, uv-0 remains more versatile across a broader range of resin types and is generally cheaper — which explains why it’s still widely used despite newer alternatives.
4. uv-0 vs. uv-531: benzophenone meets benzotriazole
now let’s move to a different class — benzotriazoles. one of the most common ones is uv-531, or 2-(2′-hydroxy-5′-methylphenyl)benzotriazole.
| property | uv-0 | uv-531 |
|---|---|---|
| chemical class | benzophenone | benzotriazole |
| absorption range | 280–380 nm | 300–385 nm |
| peak wavelength | ~330 nm | ~345 nm |
| solubility | organic solvents | similar, but better in aliphatic systems |
| color stability | moderate | excellent |
| thermal stability | moderate | high |
| cost | low | higher |
| regulatory status | generally safe | also safe, but sometimes preferred in automotive and medical sectors |
key takeaway:
uv-531 offers better color stability and less tendency to yellow over time, making it ideal for clear coatings and high-end finishes. uv-0, while effective, might cause slight discoloration in light-colored systems. however, uv-0’s lower price point keeps it relevant in cost-sensitive applications.
5. uv-0 vs. uv-327: another benzophenone contender
uv-327, or 2-(2′,4′-dimethyl-5′-hydroxyphenyl)benzotriazole, is another popular uv absorber. though technically a benzotriazole, it’s often grouped with uv-0 in performance discussions.
| property | uv-0 | uv-327 |
|---|---|---|
| chemical class | benzophenone | benzotriazole |
| absorption range | 280–380 nm | 300–385 nm |
| peak wavelength | ~330 nm | ~348 nm |
| light fastness | good | excellent |
| weather resistance | moderate | very high |
| heat resistance | moderate | high |
| toxicity | low | low |
| cost | low | medium-high |
uv-327 shines in outdoor applications where long-term weather resistance is critical — think agricultural films, automotive parts, and marine coatings. uv-0, while reliable, isn’t quite in the same league when it comes to extreme durability.
6. uv-0 vs. uv-p: the standard-bearer of benzotriazoles
uv-p, or 2-(2′-hydroxy-5′-methylphenyl)benzotriazole, is often considered the "benchmark" among benzotriazoles.
| property | uv-0 | uv-p |
|---|---|---|
| chemical class | benzophenone | benzotriazole |
| absorption range | 280–380 nm | 300–385 nm |
| peak wavelength | ~330 nm | ~345 nm |
| volatility | moderate | low |
| color retention | moderate | excellent |
| resin compatibility | broad | narrower (better in polyolefins and styrenics) |
| cost | low | medium |
uv-p is frequently used in polyolefins and engineering plastics where clarity and minimal discoloration are crucial. while uv-0 works well in general-purpose applications, uv-p is preferred in industries where aesthetics matter — such as packaging and consumer goods.
7. uv-0 vs. uv-326: long-term outdoor performance champion
uv-326, or 2-(2′-hydroxy-3′,5′-di-tert-butylphenyl)benzotriazole, is designed for tough environments.
| property | uv-0 | uv-326 |
|---|---|---|
| chemical class | benzophenone | benzotriazole |
| absorption range | 280–380 nm | 300–385 nm |
| peak wavelength | ~330 nm | ~348 nm |
| uv protection efficiency | good | excellent |
| thermal stability | moderate | high |
| volatility | moderate | very low |
| application suitability | general use | high-performance outdoor use |
| cost | low | high |
uv-326 is a top choice for applications requiring long-term uv protection, such as roofing membranes, automotive exterior parts, and construction materials. uv-0, while effective, simply can’t match the longevity and efficiency of uv-326 in harsh conditions.
8. uv-0 vs. hals: different mechanisms, complementary roles
while uv absorbers like uv-0 block uv light, hindered amine light stabilizers (hals) work differently — they trap free radicals formed during photooxidation, thereby preventing degradation.
| property | uv-0 | hals (e.g., tinuvin 770) |
|---|---|---|
| mode of action | uv absorption | radical scavenging |
| effectiveness in thick sections | yes | more effective in thick sections |
| synergy with other additives | works well with hals | often used together |
| color stability | moderate | excellent |
| cost | low | medium-high |
the key takeaway here is that uv-0 and hals are often used together. uv-0 stops uv radiation at the gate, while hals mop up any radicals that slip through. this combination is particularly powerful in polyolefin films and automotive components.
9. comparative summary table: uv-0 vs others
to wrap up this section, here’s a comprehensive comparison table summarizing the main points:
| parameter | uv-0 | uv-9 | uv-531 | uv-327 | uv-p | uv-326 | hals |
|---|---|---|---|---|---|---|---|
| chemical class | benzophenone | benzophenone | benzotriazole | benzotriazole | benzotriazole | benzotriazole | hals |
| uv absorption range | 280–380 nm | 300–400 nm | 300–385 nm | 300–385 nm | 300–385 nm | 300–385 nm | n/a |
| peak wavelength | ~330 nm | ~345 nm | ~345 nm | ~348 nm | ~345 nm | ~348 nm | – |
| solubility | organic solvents | better in oils | similar | similar | similar | similar | varies |
| volatility | moderate | moderate | low | very low | low | very low | very low |
| color stability | moderate | moderate | excellent | excellent | excellent | excellent | excellent |
| thermal stability | moderate | moderate | high | high | moderate | high | high |
| cost | low | low-moderate | moderate-high | high | moderate | high | medium-high |
| recommended use | general purpose | films, coatings | automotive, medical | outdoor, agriculture | packaging | extreme outdoor | engineering plastics, thick sections |
10. practical considerations: when to choose uv-0
despite being an older compound, uv-0 remains relevant in many industries due to several practical advantages:
- cost-effective: ideal for budget-sensitive applications.
- broad compatibility: works well in pvc, pu, acrylics, and more.
- good uv-a protection: covers the most damaging part of the solar spectrum.
- easy to incorporate: available in various forms (powder, liquid dispersions).
however, uv-0 has limitations:
- moderate volatility: can evaporate during high-temperature processing.
- limited color retention: may cause yellowing in white or light-colored materials.
- not suitable for food contact: some regulations restrict its use in food-grade applications.
11. environmental and safety aspects
from a safety standpoint, uv-0 is generally considered safe for industrial use. however, recent studies have raised concerns about the environmental persistence of certain uv absorbers.
a 2018 study published in environmental pollution highlighted the presence of benzophenone derivatives in aquatic ecosystems, suggesting potential ecological impacts (zhang et al., 2018). while uv-0 itself is not as persistent as some other uv filters (like bp-3 in sunscreens), it underscores the importance of responsible use and disposal.
on the human health front, uv-0 is classified as non-carcinogenic and poses low acute toxicity according to the national institute for occupational safety and health (niosh, 2021). still, proper handling practices should always be followed.
12. conclusion: where does uv-0 stand today?
in the ever-evolving world of uv protection, uv-0 holds its ground as a dependable, economical option for many applications. it may not have the flashy performance specs of newer benzotriazoles or the synergistic power of hals, but it gets the job done — and often at a fraction of the cost.
that said, modern applications demand more than just uv absorption. with increasing emphasis on durability, color retention, and environmental impact, formulators are turning to blends of uv absorbers and hals to achieve optimal protection.
so, if you’re looking for a cost-effective uv shield with decent performance, uv-0 is your friend. but if you’re building something that needs to survive a decade under the florida sun, you might want to reach for uv-326 or pair uv-0 with a hals co-stabilizer.
after all, uv protection isn’t a one-size-fits-all game — it’s more like a carefully orchestrated symphony 
of chemistry and engineering.
references
- zhang, x., li, y., & wang, z. (2018). occurrence and fate of uv-absorbing compounds in the aquatic environment: a review. environmental pollution, 234, 733–746.
- niosh pocket guide to chemical hazards. (2021). centers for disease control and prevention.
- marchetti, f., & pappalardo, m. (2005). photostabilization of polymeric materials. springer materials science series.
- karlsson, e., & carlsson, d. j. (1996). uv degradation and stabilization of coatings. progress in organic coatings, 28(1), 1–12.
- geuskens, g., & guillaume, m. m. (1999). stabilization of polymers against uv radiation. journal of photochemistry and photobiology a: chemistry, 125(1-3), 1–10.
- iso 4892-3:2013 plastics — methods of exposure to laboratory light sources — part 3: fluorescent uv lamps.
- astm d4329-13 standard practice for fluorescent uv exposure of plastics.
if you’ve made it this far, congratulations! you’re now equipped with enough knowledge to impress your lab mates or baffle your boss at the next formulation meeting 
. whether you choose uv-0 or its more sophisticated cousins, remember: uv protection is not just about blocking light — it’s about preserving value, quality, and performance in the face of nature’s most relentless force: the sun 
.
sales contact：sales@newtopchem.com