​​BIPB​​ (Bis(tert-butylperoxyisopropyl)benzene) is a critical organic peroxide widely used as a crosslinking agent in polymer industries. Despite sharing the ​​same molecular formula (C₂₀H₃₄O₄)​​, ​​CAS 25155-25-3​​ and ​​CAS 2212-81-9​​ represent distinct chemical isomers with divergent properties and applications. Here’s a breakdown of their key differences:

🔬 1. ​​Chemical Structure and Isomerism​​

​​CAS 25155-25-3​​:

​​Systematic Name​​: 1,4-Bis(2-(tert-butylperoxy)propan-2-yl)benzene.

​​Isomer Type​​: Para-isomer (1,4-disubstituted benzene ring).

​​Purity Focus​​: Minimizes toxic ortho-isomers, reducing health risks.

​​CAS 2212-81-9​​:

​​Systematic Name​​: 1,3-Bis(2-(tert-butylperoxy)propan-2-yl)benzene.

​​Isomer Type​​: Meta-isomer (1,3-disubstituted benzene ring) ​​sold as an isomer mixture​​.

​​Commercial Aliases​​: Marketed as ​​Perkadox® 14S​​ or ​​"Odorless DCP"​​.

⚖️ 2. ​​Physical Properties​​

Property ​​CAS 25155-25-3​​ ​​CAS 2212-81-9​​

​​Melting Point​​ 44–48°C 43–49°C

​​Density​​ 1.63 g/mL (25°C) 0.974 g/mL

​​Solubility​​ Soluble in alcohols, ethers 40 μg/L in water (20°C)

​​Odor Profile​​ Low-odor formulations ​​Explicitly "Odorless"​​

🏭 3. ​​Industrial Applications​​

​​CAS 25155-25-3​​:

Primarily used as a ​​radical initiator​​ for polymerization.

Functions in ​​luminescent reactions​​ and as a ​​rubber plasticizer​​.

​​CAS 2212-81-9​​:

​​Dominant crosslinker​​ for:

✅ Chlorinated polyethylene (CPE)

✅ Ethylene-propylene-diene monomer (EPDM)

✅ Silicone rubbers.

​​Key Advantage​​: Requires ​​~33% less dosage​​ than conventional DCP (dicumyl peroxide) for equivalent efficacy.

⚠️ 4. ​​Safety and Regulatory Profiles​​

Parameter ​​CAS 25155-25-3​​ ​​CAS 2212-81-9​​

​​Risk Phrases​​ R8 (Fire hazard), R36/37 (Eye/respiratory irritation) R7 (Fire hazard), R36 (Eye irritation)

​​Safety Labels​​ Toxic (Class Xn), Oxidizer (Class O) Irritant (Xi), Oxidizer (O)

​​Transport Code​​ UN 3106 (Class 5.2) UN 3106 (Class 5.2)

⚠️ Both require ​​strict storage​​ away from combustibles and use with PPE (gloves/goggles).

💎 5. ​​Commercial and Functional Distinctions​​

​​Toxicity​​:

​​CAS 25155-25-3​​: Toxicity linked to residual ortho-isomers; refined grades minimize this.

​​CAS 2212-81-9​​: Lower acute toxicity; preferred in odor-sensitive applications (e.g., food-grade rubber).

​​Performance​​:

​​CAS 2212-81-9​​ offers ​​superior scorch safety​​ and processing stability in rubber vulcanization.

💎 ​​Conclusion: Choosing the Right BIPB​​

While both compounds fall under the ​​BIPB umbrella​​, their structural isomerism dictates specialized uses:

Opt for ​​CAS 25155-25-3​​ for ​​polymerization initiation​​ and high-purity applications.

Choose ​​CAS 2212-81-9​​ for ​​efficient, odorless crosslinking​​ in rubber and plastic manufacturing.

💡 ​​Pro Tip​​: Verify isomer composition in technical datasheets—​​meta​​-isomer dominance defines CAS 2212-81-9’s performance.

Understanding these distinctions ensures optimal material selection, regulatory compliance, and operational safety. For sourcing details, refer to suppliers like MedChemExpress (CAS 25155-25-3) or J&K Scientific (CAS 2212-81-9).