2,5-Di-Tert-Butylhydroquinone

YINOX DTBHQ
2,5-Di-Tert-Butylhydroquinone
C14H22O2
Molecular Weight:222
CAS Number: 88-58-4
Typical Properties:
Appearance White to tan crystals
Assay 99 wt %
Specific Gravity 1.07
Melting Point 215¯C (419¯F)
Boiling Point 321¯C (610¯F)
Flash Point Cleveland Open Cup 216¯C (420¯F)
Autoignition Temperature 421¯C (790¯F)
Solubility @ 25?(77ºF)
in Water
Insoluble
In Caustic
Insoluble
In Acetone
25 wt %
In Ethanol (95%)
17 wt %
In Ethyl Acetate
31 wt %
In Toluene
< 1 wt %
In Styrene
< 5 wt %

DTBHQ is generally used as a polymerisation inhibitor, an antioxidant and a stabiliser. It is used mostly in industrial applications, particularly in rubbers, adhesive and adhesive films, paints, and monomers.

DTBHQ is often used as a polymerisation inhibitor in applications requiring inhibitors exhibiting low vapour pressure or short induction periods. Such uses include the protection of monomers during distillations, when monomers are used as chemical intermediates, and in the prevention of cross-linking during the preparation of unsaturated polyesters. When added to unsaturated polyesters, DTBHQ provides good stability during processing and storage without adversely prolonging the cure. Samples treated with DTBHQ have shown little gel time drift during storage tests.

DTBHQ in the rubber industry is known to be used as a stopping agent, antioxidant, and colour stabiliser. It is reported that much more efficient use of DTBHQ as a stopping agent is achieved by adding it to the polymerisation recipe as an emulsion. DTBHQ has also been employed as a stabiliser in the Diazo-initiated copolymerisation of styrene with butadiene. Drying oils from 80:20 butadiene:styrene copolymers can be inhibited with 0.01% - 0.2% DTBHQ to prevent viscosity increase on standing. The use of 2% DTBHQ in a rubber composition containing N,N-di-2-naphthyl-p-phenylenediamine as an antioxidant has been found to inhibit the formation of a pink discoloration in vulcanised rubber articles.

As a stabiliser, DTBHQ may be added to various compositions. For example, solutions of polyacrylonitrile may be stabilised against the development of objectionable discoloration by the addition of DTBHQ to the solvent prior to addition of the polymer. DTBHQ, at a concentration of 0.5%, is a useful heat and light stabiliser for the pressure-sensitive adhesives based on poly (vinyl ethyl ether) resins. It is reported that the sweetening of hydrocarbon oils by contact with an alkali solution and oxygen can be accelerated by the presence of DTBHQ. The alkali solution is also more readily regenerated when these compounds are present.

Other compositions stabilised by DTBHQ include solutions of gasoline antioxidants in hydrocarbon solvents, solutions of pyridine dicarboxylic acid esters, and aqueous dispersions of haloethylene polymers. DTBHQ also inhibits attack by oxygen on the unsaturated paint resins and