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Terephthalic acid

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Terephthalic acid Basic information

Product Name:
Terephthalic acid
CAS:
100-21-0
MF:
C8H6O4
MW:
166.13
EINECS:
202-830-0
Mol File:
100-21-0.mol
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Terephthalic acid Chemical Properties

Melting point:
300 °C
Boiling point:
214.32°C (rough estimate)
Density 
1,51 g/cm3
vapor pressure 
<0.01 mm Hg ( 20 °C)
refractive index 
1.5100 (estimate)
Flash point:
260°C
storage temp. 
0-6°C
solubility 
15mg/l (experimental)
pka
3.51(at 25℃)
form 
Crystalline Powder
color 
White
Water Solubility 
slightly soluble in water (0,017 g/L at 25°C)
Merck 
14,9162
BRN 
1909333
Stability:
Stable. Combustible. Incompatible with strong oxidizing agents.
CAS DataBase Reference
100-21-0(CAS DataBase Reference)
EPA Substance Registry System
Terephthalic acid (100-21-0)
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Safety Information

Hazard Codes 
Xi
Risk Statements 
36/37/38
Safety Statements 
26-36
WGK Germany 
3
RTECS 
WZ0875000
Autoignition Temperature
925 °F
TSCA 
Yes
HS Code 
2917 36 00
Toxicity
LD50 orally in Rabbit: > 6400 mg/kg

MSDS

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Terephthalic acid Usage And Synthesis

Description

Terephthalic acid is the organic compound with formula C6H4(COOH)2. This colourless solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several million tones are produced annually. It is one of three isomeric phthalic acids.

Chemical Properties

Terephthalic acid is poorly soluble in water and alcohols, consequently up until around 1970 most crude terephthalic acid was converted to the dimethyl ester for purification. It sublimates when heated.

Chemical Properties

TPA is a white crystalline solid.

Chemical Properties

white powder

Uses

Terephthalic acid is a benzenepolycarboxylic acid with potential anti-hemorrhagic properties.

Uses

1,4-benzenedicarboxylic acid is mainly used for the production of poly (ethylene terephthalate). Also production of plasticizer dioctyl phthalate (DOTP) and polyester plasticized agents. 1,4-benzenedicarboxylic acid and polyhydric alcohols have a condensation reaction withd iethylene glycol, triethylene glycol, glycerol, propylene glycol, butylene glycol, etc. preparation of the polyester plasticizer.

Definition

ChEBI: A benzenedicarboxylic acid carrying carboxy groups at positions 1 and 4. One of three possible isomers of benzenedicarboxylic acid, the others being phthalic and isophthalic acids.

Application

Virtually the entire world's supply of terephthalic acid and dimethyl terephthalate are consumed as precursors to polyethylene terephthalate (PET). World production in 1970 was around 1.75 million tones. By 2006, global purified terephthalic acid (PTA) demand had exceeded 30 million tonnes.
There is a smaller, but nevertheless significant, demand for terephthalic acid in the production of poly butylene terephthalate and several other engineering polymers.

Production Methods

Terephthalic acid is produced by oxidation of p-xylene by oxygen in air:
This reaction proceeds through a p-toluic acid intermediate which is then oxidized to terephthalic acid. In p-toluic acid, deactivation of the methyl by the electron withdrawing carboxylic acid group makes the methyl one tenth as reactive as xylene itself, making the second oxidation significantly more difficult . The commercial process utilizes acetic acid as solvent and a catalyst composed of cobalt and manganese salts, with a bromide promoter.

General Description

White powder.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

Terephthalic acid is a carboxylic acid. Terephthalic acid donates hydrogen ions if a base is present to accept them. This "neutralization" generates substantial amounts of heat and produces water plus a salt. Insoluble in water but even "insoluble" carboxylic acids may absorb enough water from the air and dissolve sufficiently in Terephthalic acid to corrode or dissolve iron, steel, and aluminum parts and containers. May react with cyanide salts to generate gaseous hydrogen cyanide. Will react with solutions of cyanides to cause the release of gaseous hydrogen cyanide. Flammable and/or toxic gases and heat are generated by reaction with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. React with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still heat. Can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. May initiate polymerization reactions; may catalyze (increase the rate of) chemical reactions.

Fire Hazard

Flash point data for Terephthalic acid are not available. Terephthalic acid is probably combustible.

Safety Profile

Moderately toxic by intravenous and intraperitoneal routes. Mildly toxic by ingestion. An eye irritant, Can explode during preparation. When heated to decomposition it emits acrid smoke and irritating fumes.

Potential Exposure

TPA is used primarily in the production of polyethylene terephthalate polymer for the fabrication of polyester fibers and films. A high-volume production chemical in the United States.

Purification Methods

Purify the acid via the sodium salt which, after crystallisation from water, is re-converted to the acid by acidification with mineral acid. Filter off the solid, wash it with H2O and dry it in a vacuum. The S-benzylisothiuronium salt has m 204o (from aqueous EtOH). [Beilstein 9 IV 3301.]

Incompatibilities

Combustible; dust may form an explosive mixture with air. Compounds of the carboxyl group react with all bases, both inorganic and organic (i.e., amines) releasing substantial heat, water and a salt that may be harmful. Incompatible with arsenic compounds (releases hydrogen cyanide gas), diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides (releasing heat, toxic and possibly flammable gases), thiosulfates and dithionites (releasing hydrogen sulfate and oxides of sulfur). Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.

Waste Disposal

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed.

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Terephthalic acidSupplierMore

Shanghai Aladdin Bio-Chem Technology Co.,LTD Gold
Tel:
021-20337333/400-620-6333
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sale@aladdin-e.com
Aikon International Limited Gold
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025-66151770,13813800073//qq:2885670560
Email:
lwan@aikonchem.com
J & K SCIENTIFIC LTD.
Tel:
010-82848833- ;010-82848833-
Email:
jkinfo@jkchemical.com;market6@jkchemical.com
Meryer (Shanghai) Chemical Technology Co., Ltd.
Tel:
21-61259100-
Email:
sh@meryer.com
future industrial shanghai co., ltd
Tel:
400-0066-400;021-60496031
Email:
sales@jonln.com
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