Inhibitors

Inhibitor 701 – 4-Hydroxy-TEMPO (CAS 2226-96-2)

Chemical & Physical Summary

• IUPAC Name: 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, commonly known as TEMPOL.

• Properties: Orange crystalline powder; molecular weight ~172.24 g/mol; melting point ~69-72 °C. Soluble in water and diverse organic solvents.

• Key Functionality: Acts as a stable nitroxide radical; effectively inhibits polymerization in monomers such as acrylates, methacrylates, acrylic acid, acrylonitrile, styrene, and butadiene. Also exhibits radical-scavenging and spin-trapping abilities and is utilized in redox chemistry and biological research.

Inhibitor 702 – 4-Oxo-TEMPO (CAS 2896-70-0)

Chemical & Physical Summary

• IUPAC Name: 4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl, known as TEMPONE.

• Properties: Orange-red powder or crystalline form; molecular weight ~170.2 g/mol; melting point around 35-41 °C. Soluble across a wide range of solvents (water, ethanol, acetone, DMSO, benzene, ether, etc.).

• Key Functionality: A robust nitroxide radical with superior polymerization inhibition compared to conventional inhibitors. Widely used in EPR/ESR as a spin-trap and in monitoring radical processes.

Inhibitor 706 – Bis-TEMPO Ester (CAS 2516-92-9)

Chemical & Physical Summary

• Chemical Name: Bis(1-λ¹-oxidanyl-2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, a high-molecular-weight nitroxide-based ester. unitechem.en.made-in-china.com

• Properties: Brown-reddish powder; purity ≥99%; low moisture (≤0.5%), ash ≤0.1%; melting point ~99-103 °C. unitechem.en.made-in-china.com

• Key Advantages: High boiling point and increased molecular weight enhance resistance to vacuum evaporation and thermal degradation. Exhibits excellent polymerization inhibition performance—especially beneficial under elevated temperature and low-pressure conditions.