| CAS
NO. |
88-32-4
(2-tert-Butyl-4-hydroxyanisole)
121-00-6
(3-tert-Butyl-4-hydroxyanisole)
25013-16-5
(Mixture) |
|
| EINECS
NO. |
2044427,
246-563-8 |
| FORMULA |
(CH3)3CC6H3(OCH3)OH |
| MOL
WT. |
180.24 |
|
H.S.
CODE
|
|
|
TOXICITY
|
|
| SYNONYMS |
2(3)-t-Butylhydroquinone monomethyl ether;
|
| 2(3)-tert-Butyl-4-hydroxyanisole; antioxyne b; BHA; BOA;
Butyl Hydroxyanisole; tert-butyl-4-hydroxyanisole;
tert-butyl-4-methoxyphenol; tert-butylhydroxyanisole; Vertac; |
| DERIVATION |
|
|
CLASSIFICATION
|
|
|
PHYSICAL AND CHEMICAL PROPERTIES
|
| PHYSICAL
STATE |
white crystals
or crystalline powder |
| MELTING POINT |
58
- 60 C |
| BOILING
POINT |
|
| SPECIFIC GRAVITY |
|
| SOLUBILITY
IN WATER |
Insoluble |
| pH |
|
| VAPOR DENSITY |
6.2 |
|
REFRACTIVE
INDEX
|
|
|
NFPA
RATINGS
|
Health: 2; Flammability: 1; Reactivity: 0 |
|
AUTOIGNITION
|
|
| FLASH
POINT |
|
| STABILITY |
Stable
under ordinary conditions. |
|
GENERAL
DESCRIPTION & APPLICATIONS
|
|
Butylated hydroxytoluene
(BHT), chemically 2,6-di-tert-butyl-p-cresol (DBPC), is
a white crystalline solid with a faint characteristic odor. It is insoluble in
water and in propylene glycol, but is freely soluble in alcohol. It is obtained
by alkylation of p-cresol with isobutene or by monobutylation of m,p-cresol
mixtures. BHT is used as a chemical antioxidant for food, cosmetics, and
pharmaceuticals much like butylated hydroxyanisole (BHA). BHA is insoluble in
water, but is freely soluble in alcohol and in propylene glycol. BHA is the
mixture of 3-tert-buryl-4-hydroxyanisole (typically
90% w/w) and 2-tert-butyl-4-hydroxyanisole. These phenol
derivatives react with the free radicals (called free radical scavengers) can
slow the rate of autoxidation that can lead to changes in the food's color and
taste. Other antioxidants for food are phosphoric acid, citric acid, gallic acid,
ascorbic acid and their esters which form complexes with the pro-oxidative metal
traces. Antimicrobial process is also important in preserving foods. BHT and
BHA are used as an antioxidant in plastics, elastomers and petroleum
(lubes, greases and waxes), practically bigger market size than food field. BHT
is also used as a stabilizer to inhibit the auto-polymerization
of organic peroxides. |
| SALES
SPECIFICATION |
| APPEARANCE
|
white crystals
or crystalline powder |
CONTENT
AS C11H16O2 |
98.5%
min
|
|
HEAVY
METALS
|
10ppm
max
|
|
RESIDUE
ON IGNITION
|
0.05%
max
|
|
MOISTURE
|
0.1%
max
|
| TRANSPORTATION |
| PACKING |
25kgs
in bag |
| HAZARD CLASS |
|
| UN
NO. |
|
| OTHER
INFORMATION |
|
Hazard
Symbols: XN, Risk Phrases: 22-40, Safety
Phrases: 36/37 |
|
GENERAL
DESCRIPTION OF ANTIOXIDANT
|
Antioxidant is a substance added in small quantities to hydrocarbons which are
susceptible to oxidation, such as rubbers, plastics, foods, and oils to inhibit
or slow oxidative processes, while being itself oxidized. Antioxidants work in
two different ways. In primary antioxidants (also called free-radical
scavengers), antioxidative activity is implemented by the donation of an
electron or hydrogen atom to a radical derivative. These antioxidants are
usually hindered amines (p-Phenylene diamine, trimethyl dihydroquinolines,
alkylated diphenyl amines) or substituted phenolic compounds with one or more
bulky functional groups such as a tertiary butyl at 2,6 position commonly.
Butylated hydroxytoluene (BHT) is a common example of hindered phenolic
antioxidant. The reaction rate, or carbocation stability, in SN1 mechanism is 3° > 2° > 1° > CH3
(no SN1) so, tertiary alkyl moiety exists in lots of phenolic antioxidant
compounds. Primary antioxidants are free radical scavengers which combine with
peroxy radicals and break autocatalytic cycle. In secondary antioxidants ( also
called peroxide decomposers), activity is implemented by the removal of an
oxidative catalyst and the consequent prevention of the initiation of oxidation.
Examples of peroxide decomposer type of antioxidant are trivalent phosphorous
and divalent sulfurcontaining compound such as sulfides, thiodipropionates and
organophosphites. Synergistic effect is expected when primary antioxidants are
used together with secondary antioxidants as primary antioxidants are not very
effective against the degradation by UV oxidation. Sometimes, chelating agents
are added to scavenge metal impurities which can initiate decomposition.
|