Terephthalic Acid

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  • Identifiers

    CAS number
    100-21-0

    Molecular formula
    C8H6O4

    SMILES
    C1=CC(=CC=C1C(=O)O)C(=O)O

    Safety labels

    Irritant
    Irritant

  • Odor profile

    Fragrance
    Odorless 62.12%
    Phenolic 46.97%
    Sour 43.67%
    Burnt 39.62%
    Balsamic 34.87%
    Nutty 33.22%
    Sharp 26.86%
    Aromatic 26.68%
    Bitter 24.31%
    Medicinal 21.87%

     

    Flavor
    Odorless 58.62%
    Nutty 47.6%
    Sour 46.14%
    Faint 44.68%
    Phenolic 44.05%
    Balsam 36.48%
    Mild 36.45%
    Balsamic 29.58%
    Very mild 28.06%
    Urine 26.7%

     

    Odor impact est.
    Low

  • Properties

    XLogP3-AA
    2.0

    pKa est.
    4.77 (weak acid)

    Molecular weight
    166.13 g/mol

    Vapor pressure est.

    • hPa @ 20°C
    • hPa @ 25°C

    Evaporation rate
    Ultra slow

    Melting point expt.

    • Sublimes (NTP, 1992)
    • 427 °C (sealed tube)
    • > 300 °C
    • sublimes

    Boiling point

    • greater than 572 °F at 760 mmHg (sublimes without melting) (NTP, 1992)
    • >572 °F (sublimes)

    Flash point

    • 229.46 ˚C est.
    • 260 °C
    • 500 °F (260 °C) (Open cup)

    Solubility expt.

    • Insoluble (NTP, 1992)
    • Insoluble in chloroform, ether, acetic acid; slightly soluble in alcohol; soluble in alkalies
    • Solubilities at 25 °C (g/100 g solvent): water = 0.0017, glacial acetic acid = 0.013, methanol = 0.1, dimethylformamide = 6.7, dimethyl sulfoxide = 19.0
    • In water, 15 mg/L at 20 °C
    • 0.015 mg/mL at 20 °C
    • Solubility in water, g/100ml at 20 °C: 0.28

  • Synonyms

    • TEREPHTHALIC ACID
    • 100-21-0
    • p-Phthalic acid
    • 1,4-Benzenedicarboxylic acid
    • benzene-1,4-dicarboxylic acid
    • p-Dicarboxybenzene
    • 1,4-dicarboxybenzene
    • p-Benzenedicarboxylic acid
    • p-Carboxybenzoic acid
    • Acide terephtalique
    • Tephthol
    • para-Phthalic acid
    • 4-Carboxybenzoic Acid
    • TA-33MP
    • Kyselina tereftalova
    • WR 16262
    • NSC 36973
    • TA 12
    • 6S7NKZ40BQ
    • DTXSID6026080
    • NSC-36973
    • DTXCID006080
    • CHEBI:15702
    • 4-oxoniocarbonylbenzoate
    • P-PTHALIC ACID
    • RefChem:6289
    • 202-830-0
    • 685-562-0
    • hydron;terephthalate
    • p-Phthalate
    • Kyselina terftalova
    • MFCD00002558
    • Benzene-p-dicarboxylic acid
    • HSDB 834
    • terephthalicacid
    • Acide terephtalique [French]
    • Kyselina tereftalova [Czech]
    • CAS-100-21-0
    • CCRIS 2786
    • EINECS 202-830-0
    • UNII-6S7NKZ40BQ
    • BRN 1909333
    • terephtalic acid
    • AI3-16108
    • P-Phthelate
    • P-Phthelic acid
    • UB7
    • p-Benzenedicarboxylate
    • terephthalsäure
    • Benzene-p-dicarboxylate
    • benzene-1,4-dioic acid
    • WLN: QVR DVQ
    • Terephthalic acid, 97%
    • Terephthalic acid, 98%
    • benzoic acid, 4-carboxy-
    • EC 202-830-0
    • SCHEMBL1655
    • para-benzenedicarboxylic acid
    • Benzene, p-dicarboxylic acid
    • Terephthalic acid (Standard)
    • Tranexamic Acid Impurity 18
    • 4-09-00-03301 (Beilstein Handbook Reference)
    • BIDD:ER0245
    • TEREPHTHALIC ACID [MI]
    • orb1299281
    • orb3025041
    • SCHEMBL2780243
    • SCHEMBL8418372
    • SCHEMBL8873876
    • CHEMBL1374420
    • TEREPHTHALIC ACID [HSDB]
    • Benzene, 1,4-Dicarboxylic acid
    • HMS5085O12
    • HY-W010098R
    • NSC36973
    • STR02759
    • Tox21_201659
    • Tox21_303229
    • EBC-03308
    • s6251
    • SBB060285
    • STL281856
    • Terephthalic acid, analytical standard
    • AKOS000119464
    • MSK26006-100M
    • CS-W010814
    • FT28042
    • HY-W010098
    • NCGC00091618-01
    • NCGC00091618-02
    • NCGC00091618-03
    • NCGC00257014-01
    • NCGC00259208-01
    • AC-10250
    • BP-21157
    • NS00003928
    • ST50824887
    • T0166
    • EN300-18042
    • C06337
    • G73905
    • Terephthalic acid, SAJ special grade, >=98.0%
    • AE-562/40217759
    • F358209
    • Q408984
    • Terephthalic acid Solution in Methanol, 100ug/mL
    • Terephthalic acid, Vetec(TM) reagent grade, 98%
    • Z57127536
    • 211863-90-0
    • 100-21-0

  • Applications

    Terephthalic acid (CAS 100-21-0) is a key diacid used as the principal monomer for making polyesters, notably PET and PBT, enabling fibers, films, and PET beverage packaging. It is also a feedstock for unsaturated polyester resins used in coatings, paints, adhesives, and composites. Additionally, it serves in high-temperature, engineering polyester polymers for electronics and automotive components, and in specialty packaging materials and laminates.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 16.69
    methanol 35.72
    isopropanol 8.28
    water 1.65
    ethyl acetate 0.95
    n-propanol 7.68
    acetone 2.25
    n-butanol 3.45
    acetonitrile 0.34
    DMF 44.18
    toluene 0.24
    isobutanol 2.64
    1,4-dioxane 3.09
    methyl acetate 1.64
    THF 1.95
    2-butanone 2.24
    n-pentanol 1.73
    sec-butanol 6.8
    n-hexane 0.27
    ethylene glycol 13.3
    NMP 40.94
    cyclohexane 0.12
    DMSO 131.12
    n-butyl acetate 1.18
    n-octanol 2.6
    chloroform 0.46
    n-propyl acetate 0.21
    acetic acid 2.82
    dichloromethane 0.7
    cyclohexanone 0.33
    propylene glycol 8.75
    isopropyl acetate 0.63
    DMAc 28.63
    2-ethoxyethanol 10.38
    isopentanol 2.44
    n-heptane 0.34
    ethyl formate 0.9
    1,2-dichloroethane 0.83
    n-hexanol 2.91
    2-methoxyethanol 33.39
    isobutyl acetate 0.03
    tetrachloromethane 0.45
    n-pentyl acetate 1.28
    transcutol 34.97
    n-heptanol 2.88
    ethylbenzene 0.24
    MIBK 0.83
    2-propoxyethanol 11.84
    tert-butanol 9.86
    MTBE 3.3
    2-butoxyethanol 7.7
    propionic acid 3.53
    o-xylene 0.77
    formic acid 11.95
    diethyl ether 3.36
    m-xylene 0.35
    p-xylene 0.15
    chlorobenzene 0.11
    dimethyl carbonate 1.89
    n-octane 0.15
    formamide 30.3
    cyclopentanone 1.11
    2-pentanone 1.26
    anisole 0.86
    cyclopentyl methyl ether 1.08
    gamma-butyrolactone 2.39
    1-methoxy-2-propanol 20.56
    pyridine 1.28
    3-pentanone 1.49
    furfural 3.85
    n-dodecane 0.08
    diethylene glycol 17.99
    diisopropyl ether 0.9
    tert-amyl alcohol 10.11
    acetylacetone 1.35
    n-hexadecane 0.09
    acetophenone 0.96
    methyl propionate 2.19
    isopentyl acetate 0.83
    trichloroethylene 0.9
    n-nonanol 2.38
    cyclohexanol 0.95
    benzyl alcohol 0.96
    2-ethylhexanol 1.32
    isooctanol 1.62
    dipropyl ether 1.56
    1,2-dichlorobenzene 0.3
    ethyl lactate 1.19
    propylene carbonate 0.93
    n-methylformamide 16.03
    2-pentanol 3.22
    n-pentane 0.39
    1-propoxy-2-propanol 8.6
    1-methoxy-2-propyl acetate 3.3
    2-(2-methoxypropoxy) propanol 9.88
    mesitylene 0.42
    ε-caprolactone 0.81
    p-cymene 0.7
    epichlorohydrin 2.37
    1,1,1-trichloroethane 0.33
    2-aminoethanol 16.57
    morpholine-4-carbaldehyde 14.82
    sulfolane 15.47
    2,2,4-trimethylpentane 0.32
    2-methyltetrahydrofuran 1.77
    n-hexyl acetate 1.98
    isooctane 0.14
    2-(2-butoxyethoxy)ethanol 11.71
    sec-butyl acetate 0.15
    tert-butyl acetate 1.44
    decalin 0.09
    glycerin 16.55
    diglyme 17.79
    acrylic acid 3.95
    isopropyl myristate 0.73
    n-butyric acid 1.48
    acetyl acetate 0.42
    di(2-ethylhexyl) phthalate 1.56
    ethyl propionate 0.47
    nitromethane 4.34
    1,2-diethoxyethane 3.75
    benzonitrile 0.22
    trioctyl phosphate 1.16
    1-bromopropane 0.53
    gamma-valerolactone 2.33
    n-decanol 1.62
    triethyl phosphate 1.27
    4-methyl-2-pentanol 1.52
    propionitrile 0.45
    vinylene carbonate 0.62
    1,1,2-trichlorotrifluoroethane 8.43
    DMS 1.78
    cumene 0.25
    2-octanol 1.89
    2-hexanone 0.34
    octyl acetate 1.12
    limonene 1.01
    1,2-dimethoxyethane 6.98
    ethyl orthosilicate 1.16
    tributyl phosphate 1.13
    diacetone alcohol 5.53
    N,N-dimethylaniline 1.59
    acrylonitrile 0.73
    aniline 0.93
    1,3-propanediol 11.91
    bromobenzene 0.08
    dibromomethane 0.51
    1,1,2,2-tetrachloroethane 1.31
    2-methyl-cyclohexyl acetate 0.61
    tetrabutyl urea 2.69
    diisobutyl methanol 1.24
    2-phenylethanol 1.72
    styrene 0.18
    dioctyl adipate 1.1
    dimethyl sulfate 8.27
    ethyl butyrate 0.72
    methyl lactate 5.95
    butyl lactate 3.38
    diethyl carbonate 0.65
    propanediol butyl ether 8.88
    triethyl orthoformate 1.05
    p-tert-butyltoluene 0.84
    methyl 4-tert-butylbenzoate 5.46
    morpholine 5.43
    tert-butylamine 4.85
    n-dodecanol 1.02
    dimethoxymethane 14.15
    ethylene carbonate 0.34
    cyrene 5.07
    2-ethoxyethyl acetate 3.1
    2-ethylhexyl acetate 0.61
    1,2,4-trichlorobenzene 0.51
    4-methylpyridine 0.69
    dibutyl ether 0.88
    2,6-dimethyl-4-heptanol 1.24
    DEF 5.41
    dimethyl isosorbide 10.44
    tetrachloroethylene 1.78
    eugenol 5.35
    triacetin 2.3
    span 80 5.86
    1,4-butanediol 3.6
    1,1-dichloroethane 0.32
    2-methyl-1-pentanol 1.39
    methyl formate 5.31
    2-methyl-1-butanol 2.9
    n-decane 0.16
    butyronitrile 0.29
    3,7-dimethyl-1-octanol 1.81
    1-chlorooctane 0.53
    1-chlorotetradecane 0.19
    n-nonane 0.15
    undecane 0.11
    tert-butylcyclohexane 0.1
    cyclooctane 0.1
    cyclopentanol 1.56
    tetrahydropyran 0.7
    tert-amyl methyl ether 4.59
    2,5,8-trioxanonane 13.59
    1-hexene 0.39
    2-isopropoxyethanol 3.39
    2,2,2-trifluoroethanol 2.69
    methyl butyrate 0.41

    Scent© AI

1 4

IFRA standard 51

Recommendation
No restriction
Maximum acceptable concentrations in the finished product (%)
Category 1
Products applied to the lips
 No restriction Category 7A
Rinse-off products applied to the hair with some hand contact
 No restriction
Category 2
Products applied to the axillae
 No restriction Category 7B
Leave-on products applied to the hair with some hand contact
 No restriction
Category 3
Products applied to the face/body using fingertips
 No restriction Category 8
Products with significant anogenital exposure
 No restriction
Category 4
Products related to fine fragrance
 No restriction Category 9
Products with body and hand exposure, primarily rinse off
 No restriction
Category 5A
Body lotion products applied to the body using the hands (palms), primarily leave on
 No restriction Category 10A
Household care products with mostly hand contact
 No restriction
Category 5B
Face moisturizer products applied to the face using the hands (palms), primarily leave on
 No restriction Category 10B
Household care products with mostly hand contact, including aerosol/spray products (with potential leave-on skin contact)
 No restriction
Category 5C
Hand cream products applied to the hands using the hands (palms), primarily leave on
 No restriction Category 11A
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate without UV exposure
 No restriction
Category 5D
Baby Creams, baby Oils and baby talc
 No restriction Category 11B
Products with intended skin contact but minimal transfer of fragrance to skin from inert substrate with potential UV exposure
 No restriction
Category 6
Products with oral and lip exposure
 No restriction Category 12
Products not intended for direct skin contact, minimal or insignificant transfer to skin
 No restriction