Product Introduce

Product Name	UV-329
Chemical Name	2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol
CAS No.	3147-75-9
Type	benzotriazole UV absorber
Molecular Formula	C20H25N3O
Molecular Weight	323g/mol
Appearance	White to light yellow powder
Melting Point	102-108℃
Ash	≤0.1%
Assay	≥99.0%
Density	1.18g/cm3

UV-329 belongs to the hydroxyphenyl benzotriazole family of ultraviolet absorbers. Its primary function is to absorb harmful UV radiation before it can initiate photochemical reactions within the polymer.When polymers are exposed to sunlight or artificial UV radiation for extended periods, UV energy can initiate chain degradation and photooxidation. This may result in yellowing, discoloration, surface cracking, loss of gloss, embrittlement and deterioration of mechanical properties.

By incorporating UV-329 into plastics and polymer formulations, manufacturers can reduce the impact of UV radiation and improve the long-term appearance and physical integrity of finished products. Technical data from commercial UV-329 products also indicates its suitability for molded articles, films, sheets and fibers exposed to outdoor weathering.

Solubility @20 ℃ (g/100g solvent)
EthylAlcohol	0.6
Chloroform	37
Ethyl acetate	15
n-hexane	6
Benzene	32
Cyclohexane	15
Water	＜0.01
Methylene Chloride	38
Acetone	9
Styrene	33
n-Heptane	7.4

How Does UV-329 Work?

The main mechanism of UV-329 is UV absorption rather than free-radical scavenging.The benzotriazole structure selectively absorbs high-energy ultraviolet radiation and converts the absorbed energy into a lower-energy form, thereby reducing the amount of UV radiation that reaches the polymer chains.This helps slow down UV-induced degradation and can improve the material's resistance to:

UV aging, yellowing, surface cracking, loss of gloss, embrittlement and mechanical property deterioration.

UV-329 has particularly low absorption in the visible-light region, making it useful for applications where the appearance and transparency of the finished product need to be maintained.

Application of UV-329

UV-329 is suitable for a wide range of polymer applications and is commonly used in polycarbonate (PC), polyester, PVC, polystyrene (PS), PMMA, ABS resin, polyolefins, epoxy resins, and other organic polymer systems. Additionally, it can be applied in films, sheets, fibers, coatings, adhesives, and elastomeric materials.

Packaging and Storage

UV-329 should be stored in tightly closed original container in a cool,dry and well-ventilated area.Avoid prolonged exposure to moisture,direct sunlight and excessive heat.Packaging can be supplied accrding to the supplier's standard or customer requirements.

FAQ

Q: What is the typical dosage of UV-329?

A: A typical recommended range is approximately 0.1–1.0%, depending on the polymer and application. The optimum dosage should be determined through formulation and weathering tests rather than applied as a universal concentration.

Q: Can UV-329 be used in polycarbonate?

A: Yes. UV-329 for polycarbonate is a common application consideration, particularly where protection against UV-induced yellowing and degradation is required. It is also suitable for other engineering plastics and transparent polymer systems.

Q: What is the difference between UV-329 and UV-328?

A: Both UV-329 and UV-328 are benzotriazole UV absorbers, but they have different molecular structures and therefore different performance profiles and application preferences. UV-329 is particularly well established for engineering plastics and applications requiring low visible-light absorption and good performance in transparent or light-colored materials.

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