Introduction to Pure Meta-BIPB
Bis(tert-butylperoxyisopropyl)benzene registered under CAS 2212-81-9 represents the pure meta-isomer of BIPB, also referred to as 1,3-BIPB. While the mixed-isomer product (CAS 25155-25-3) dominates commercial markets, the pure meta-isomer offers distinct advantages for specialized applications where isomer purity, consistent melting behavior, and tightly controlled crosslinking kinetics are paramount.
Key Facts: BIPB CAS 2212-81-9
- CAS Number: 2212-81-9
- IUPAC Name: 1,3-Bis(2-(tert-butylperoxy)isopropyl)benzene
- Molecular Formula: C20H34O4
- Molecular Weight: 338.49 g/mol
- Purity: Typically >97% meta-isomer
- Melting Range: 48-52 deg C (narrow, pure compound)
- Active Oxygen: 9.45% (theoretical)
- 10-Hour Half-Life: ~133 deg C
Manufacturing and Purity
CAS 2212-81-9 is produced by starting with pure 1,3-diisopropylbenzene rather than the technical mixed-isomer feedstock used for CAS 25155-25-3. The reaction of pure meta-diisopropylbenzene with tert-butyl hydroperoxide yields the single isomer product. Additional purification steps may be employed to achieve the >97% purity specification required for premium applications.
Specialized Applications
1. Medical-Grade Crosslinking
For medical device applications requiring peroxide-crosslinked silicone or polyethylene components, the pure meta-isomer BIPB offers tighter control over extractable and leachable profiles. The absence of para-isomer decomposition products simplifies regulatory compliance and biocompatibility testing.
2. Electronic Materials
Semiconductor packaging materials, printed circuit board laminates, and other electronic applications benefit from the consistent crosslinking behavior and minimal byproduct profile of pure meta-BIPB. Uniform crosslink density is critical for maintaining dielectric properties and dimensional stability.
3. High-Performance Composites
Advanced composite applications in aerospace and automotive sectors may specify pure meta-BIPB for critical components where variability in crosslink density from isomer distribution cannot be tolerated. The narrower decomposition temperature range provides more predictable cure behavior in precision manufacturing.
Frequently Asked Questions
Q: Is CAS 2212-81-9 worth the premium over CAS 25155-25-3?
A: For standard industrial applications (PEX pipes, general XLPE, standard rubber vulcanization), the mixed-isomer product (CAS 25155-25-3) provides excellent performance at a lower cost. The pure meta-isomer (CAS 2212-81-9) justifies its premium for applications where isomer purity directly impacts regulatory compliance, product performance specifications, or manufacturing consistency. Examples include medical devices, high-reliability electronic materials, and aerospace composites.
Q: What is the shelf life of pure meta-BIPB?
A: When stored under recommended conditions (cool, dry, below 30 deg C, in original sealed containers), pure meta-BIPB typically has a shelf life of 6-12 months from the date of manufacture. The active oxygen content should be verified before use if the material has been stored for an extended period. Periodic retesting per the manufacturer’s recommendations is advisable for critical applications.
Key Takeaways
- BIPB CAS 2212-81-9 is the pure meta-isomer (1,3-BIPB) with >97% isomeric purity.
- It offers advantages of consistent melting behavior, predictable decomposition kinetics, and minimal byproduct variation.
- Specialized applications include medical devices, electronic materials, and high-performance composites.
- For most industrial applications, the mixed-isomer product (CAS 25155-25-3) provides equivalent performance at lower cost.
- Shandong Do Sender Chemicals can supply both BIPB grades depending on application requirements.