1-Phenacylpyridinium Bromide

Name:1-Phenacylpyridinium Bromide
Abbreviation:PAPB
CAS: 16883-69-5
Molecular formula: C₁₄H₁₂BrNO

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🔬I.Core Characteristics
PAPB is a unique cationic photoinitiator belonging to the pyridinium salt class. Its mechanism of action differs entirely from traditional radical-type initiators (such as 819), exhibiting the following notable features:

Cationic Curing Mechanism: Upon light exposure, it generates strong Lewis acids (e.g., HBr) capable of initiating cationic polymerization of monomers like epoxy resins and vinyl ethers. This polymerization process is not inhibited by oxygen, enabling complete surface curing even in air.

Broad Photosensitive Wavelength Range: While inherently absorbing in the UV region, its photosensitivity can be extended to long-wave UV or even visible light by adding sensitizers (e.g., thioxanthones, anthraquinones), making it suitable for systems sensitive to UV-A or visible light.

“Dark Curing” Effect: Once initiated, cationic polymerization exhibits prolonged chain-growth active center lifetime, allowing reactions to continue for a period after light exposure ceases. This facilitates complete curing in thick films and shadowed areas.

Low Curing Shrinkage: Cationically polymerized epoxy systems exhibit minimal volume shrinkage, low internal stress, excellent substrate adhesion, and high dimensional accuracy in finished products.

Incompatible with alkali-sensitive systems: The acidic environment generated can interfere with alkali-catalyzed reactions, such as certain condensation reactions.

💡II. Primary Applications
Leveraging its cationic and dark-curing properties, PAPB is primarily utilized in the following high-end sectors:

UV-Curable Cationic Coatings and Inks:

Packaging Printing:
High-performance UV inks and clear varnishes for food and pharmaceutical packaging, favored for their low odor, oxygen-free polymerization inhibition, and strong adhesion.

Electronic Protective Coatings:
Used for encapsulation and conformal coatings on printed circuit boards and electronic components, valued for their excellent chemical resistance and dimensional stability.

Photoresists and Microelectronics:

Chemical Amplifier Photoresists:
Serves as an acid generator in deep ultraviolet lithography processes for integrated circuit manufacturing.

Optical Fiber Coatings:
Provides rapid-curing protective coatings for optical fibers.

High-Performance Composites and Adhesives:

Structural Adhesives:
Used for bonding materials like glass and metal, exhibiting low curing shrinkage and high strength.

Rapid Prototyping:
Employed in cationic 3D printing resins (e.g., certain DLP resins) to produce low-shrinkage, high-precision models.

Scientific Research:

Serves as a photosensitive acid generator in organic synthesis, catalyzing the removal of acid-sensitive protecting groups or cyclization reactions.

📌III. Storage and Export Conditions
As an organic salt chemical, PAPB requires adherence to specific protocols for storage and transportation.

1. Storage Conditions:

Environment: Store in a cool, dry, well-ventilated warehouse away from light and moisture.

Temperature: Recommended storage at room temperature or below (e.g., < 25°C). Refer to supplier recommendations for specifics.

Packaging: Use opaque containers (e.g., cardboard drums or plastic drums lined with aluminum foil bags), sealed tightly to prevent moisture absorption.

Isolation: Store separately from strong oxidizing agents and strong alkalis.

Stability: Sensitive to light and moisture; moisture absorption may affect activity and stability. Once opened, handle in a dry environment and use promptly.

2. Export Shipping Conditions:

Hazard Classification (based on typical SDS):

Generally not classified as a major hazardous material. However, may be categorized as:

Irritant substance (may cause irritation to eyes, skin, or respiratory tract).

Environmental impact (e.g., harmful to aquatic life) requires assessment based on specific data.

UN Number (UN No.):
Typically transported as a general chemical product without a specific UN number. However, final classification must be based on actual test reports and SDS.

Packaging Category:
If not classified as hazardous, packaged as general chemicals.

Packaging Requirements:
Sturdy, moisture-proof, light-shielding commercial packaging is sufficient (e.g., double-layered plastic bags sealed and placed inside paper or plastic drums).

📊 ⭐ Why Choose Us

• Reliable supply for research and commercial quantities

• Strict quality control and batch consistency

• Experience with export compliance and documentation

• Support for custom synthesis and technical consultation

📩 Contact Information

For pricing, samples, technical data, or customized specifications, please contact:

●Product Manager:Lucy Yao

Email:  lucy@coreychem.com