2,2'-Methylenebis(4-methyl-6-tert-butylphenol) is a synthetic phenolic antioxidant with the following characteristics:

Chemical Structure

• Core Structure: Comprises two phenol rings connected by a methylene (-CH?-) bridge at their 2-positions (ortho to the hydroxyl group).

• Substituents:

• Hydroxyl Group (-OH): At position 1 on each benzene ring.

• Methyl Group (-CH?): At position 4 (para to the hydroxyl).

• tert-Butyl Group (-C(CH?)?): At position 6 (ortho to the hydroxyl).

• Molecular Formula: C??H??O?.

• Molecular Weight: 340.5 g/mol.

Properties

• Physical Form: Typically a white to off-white crystalline solid.

• Solubility: Insoluble in water; soluble in organic solvents like ethanol, acetone, and toluene.

• Steric Hindrance: The bulky tert-butyl and methyl groups protect the reactive phenolic -OH, enhancing stability.

Applications

• Primary Use: Antioxidant in polymers (plastics, rubber), lubricants, and fuels to inhibit oxidative degradation.

• Mechanism: Donates hydrogen atoms from phenolic -OH groups to free radicals (e.g., peroxy radicals), forming stable phenoxy radicals that terminate chain reactions.

Synthesis

• Reaction: Condensation of two equivalents of 4-methyl-6-tert-butylphenol with formaldehyde (HCHO) under acidic or basic conditions.

• Process: Electrophilic aromatic substitution at the 2-position of each phenol unit, forming the methylene bridge.

Safety and Regulation

• Toxicity: May cause skin/eye irritation; specific toxicity data should be verified via safety databases.

• Regulatory Status: Complies with industrial chemical regulations (e.g., REACH, TSCA) for use in materials.

Key Advantages

• Efficiency: Dual phenolic groups enhance radical-scavenging capacity.

• Thermal Stability: Bulky substituents prevent volatilization at high temperatures.

This compound is valued in industries requiring durable materials resistant to oxidative breakdown.