Diboron trioxide

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  • Identifiers

    CAS number
    1303-86-2

    Molecular formula
    B2O3

    SMILES
    B(=O)OB=O

    Safety labels

    Health Hazard
    Health

  • Odor profile

    Fragrance
    Odorless 68.07%
    Pungent 28.57%
    Sharp 26.03%
    Ethereal 24.34%
    Sour 23.67%
    Fruity 23.08%
    Burnt 21.19%
    Sulfurous 18.13%
    Winey 17.08%
    Fermented 15.85%

     

  • Properties

    pKa est.
    12.59 (strong base)

    Molecular weight
    69.63 g/mol

    Melting point expt.

    • 842 °F (NIOSH, 2024)
    • 450 °C (crystal)
    • 450 °C
    • 842 °F

    Boiling point

    • 3380 °F at 760 mmHg (NIOSH, 2024)
    • 1500 °C (crystal)
    • ~1860 °C
    • 3380 °F

    Flash point

    • 6.85 ˚C est.

    Solubility expt.

    • 3 % (NIOSH, 2024)
    • Slowly soluble in 30 parts cold water; slowly soluble in 5 parts boiling water; soluble in alcohol, glycerol
    • Water solubility: 4.0% at 20 °C
    • 2.77 g/100 g water at 20 °C.
    • Solubility in water, g/l at 25 °C: 36 (moderate)
    • 3%

  • Synonyms

    • Boric anhydride
    • 1303-86-2
    • Boron trioxide
    • Boric oxide
    • Diboron trioxide
    • oxo(oxoboranyloxy)borane
    • Boron oxide (B2O3)
    • Boric acid anhydride
    • B2O3
    • CHEBI:30163
    • BORICANHYDRIDE
    • Boron Oxide Nanopowder
    • Titanium Nitride (TiN) Powder
    • DTXSID7034387
    • Boron oxide powder (-200mesh)
    • Boron oxide nanopowder (<80 nm)
    • AKOS015903863
    • Boron Trioxide Powder / B2O3 Powder
    • Boron Oxide Submicron/Powder/Nanopowder
    • Boric anhydride, 99.98% trace metals basis
    • Boric anhydride, 99.999% trace metals basis
    • Boric anhydride, puriss. p.a., >=98% (T)
    • Boric anhydride, purum p.a., >=97.0% (T)
    • E75776
    • Boric anhydride, Vetec(TM) reagent grade, 98%
    • Q411076

  • Applications

    Diboron trioxide (CAS 1303-86-2) is a key precursor and oxide source for boron-containing materials used across several industries. In glass and ceramics, it supplies boron oxide for borosilicate glasses, specialty frits and glazes, helping tailor thermal stability and chemical durability. It is employed in the manufacture of fiberglass and ceramic composites as a glass-forming oxide and as a starting material for boron-containing ceramics and refractories. In electronics and optics, formulations based on B2O3 support glass seals, coatings and insulating components derived from borosilicate glass. In metallurgy, it can function as a flux to assist melting and alloy processing. As a chemical precursor, it enables synthesis of boron-containing polymers and advanced ceramic materials. These uses depend on formulation specifics and regulatory requirements.

    gpt-5-nano

  • Solubility @25˚C

    Solvent Solubility (g/L)
    ethanol 464.69
    methanol 692.68
    isopropanol 380.78
    water 257.36
    ethyl acetate 91.95
    n-propanol 297.08
    acetone 217.73
    n-butanol 226.55
    acetonitrile 151.71
    DMF 686.32
    toluene 31.02
    isobutanol 196.09
    1,4-dioxane 214.18
    methyl acetate 128.39
    THF 389.65
    2-butanone 132.1
    n-pentanol 150.37
    sec-butanol 268.89
    n-hexane 32.38
    ethylene glycol 344.03
    NMP 310.84
    cyclohexane 19.47
    DMSO 462.58
    n-butyl acetate 44.12
    n-octanol 76.59
    chloroform 73.69
    n-propyl acetate 69.34
    acetic acid 178.5
    dichloromethane 77.81
    cyclohexanone 78.46
    propylene glycol 335.55
    isopropyl acetate 67.23
    DMAc 467.57
    2-ethoxyethanol 315.0
    isopentanol 174.83
    n-heptane 24.75
    ethyl formate 93.1
    1,2-dichloroethane 67.33
    n-hexanol 110.27
    2-methoxyethanol 577.82
    isobutyl acetate 42.39
    tetrachloromethane 30.36
    n-pentyl acetate 41.74
    transcutol 219.96
    n-heptanol 76.91
    ethylbenzene 26.47
    MIBK 81.77
    2-propoxyethanol 242.29
    tert-butanol 384.29
    MTBE 172.13
    2-butoxyethanol 148.47
    propionic acid 134.22
    o-xylene 35.4
    formic acid 216.96
    diethyl ether 177.95
    m-xylene 31.43
    p-xylene 28.63
    chlorobenzene 21.3
    dimethyl carbonate 122.89
    n-octane 11.82
    formamide 322.0
    cyclopentanone 139.01
    2-pentanone 114.29
    anisole 80.62
    cyclopentyl methyl ether 156.01
    gamma-butyrolactone 150.93
    1-methoxy-2-propanol 444.66
    pyridine 80.43
    3-pentanone 86.28
    furfural 118.33
    n-dodecane 10.65
    diethylene glycol 292.18
    diisopropyl ether 59.57
    tert-amyl alcohol 273.54
    acetylacetone 89.91
    n-hexadecane 10.62
    acetophenone 58.15
    methyl propionate 128.48
    isopentyl acetate 36.79
    trichloroethylene 61.23
    n-nonanol 66.64
    cyclohexanol 119.67
    benzyl alcohol 68.54
    2-ethylhexanol 52.69
    isooctanol 57.36
    dipropyl ether 87.12
    1,2-dichlorobenzene 21.39
    ethyl lactate 84.92
    propylene carbonate 73.62
    n-methylformamide 343.85
    2-pentanol 176.94
    n-pentane 45.19
    1-propoxy-2-propanol 153.92
    1-methoxy-2-propyl acetate 70.04
    2-(2-methoxypropoxy) propanol 119.64
    mesitylene 25.13
    ε-caprolactone 77.79
    p-cymene 21.16
    epichlorohydrin 156.08
    1,1,1-trichloroethane 46.86
    2-aminoethanol 431.79
    morpholine-4-carbaldehyde 288.91
    sulfolane 166.86
    2,2,4-trimethylpentane 21.38
    2-methyltetrahydrofuran 197.44
    n-hexyl acetate 56.03
    isooctane 16.78
    2-(2-butoxyethoxy)ethanol 145.89
    sec-butyl acetate 49.39
    tert-butyl acetate 80.14
    decalin 13.74
    glycerin 398.6
    diglyme 224.09
    acrylic acid 123.95
    isopropyl myristate 32.02
    n-butyric acid 105.82
    acetyl acetate 47.13
    di(2-ethylhexyl) phthalate 32.38
    ethyl propionate 81.26
    nitromethane 241.15
    1,2-diethoxyethane 75.13
    benzonitrile 40.37
    trioctyl phosphate 30.98
    1-bromopropane 59.21
    gamma-valerolactone 169.03
    n-decanol 53.03
    triethyl phosphate 34.97
    4-methyl-2-pentanol 97.65
    propionitrile 118.42
    vinylene carbonate 59.88
    1,1,2-trichlorotrifluoroethane 141.72
    DMS 49.77
    cumene 25.58
    2-octanol 57.74
    2-hexanone 78.38
    octyl acetate 41.62
    limonene 28.29
    1,2-dimethoxyethane 332.73
    ethyl orthosilicate 36.32
    tributyl phosphate 29.72
    diacetone alcohol 139.31
    N,N-dimethylaniline 88.45
    acrylonitrile 125.82
    aniline 70.33
    1,3-propanediol 339.26
    bromobenzene 15.38
    dibromomethane 56.96
    1,1,2,2-tetrachloroethane 68.62
    2-methyl-cyclohexyl acetate 38.59
    tetrabutyl urea 48.59
    diisobutyl methanol 39.93
    2-phenylethanol 55.21
    styrene 26.99
    dioctyl adipate 43.92
    dimethyl sulfate 146.68
    ethyl butyrate 48.83
    methyl lactate 148.0
    butyl lactate 49.97
    diethyl carbonate 37.49
    propanediol butyl ether 134.15
    triethyl orthoformate 46.68
    p-tert-butyltoluene 23.91
    methyl 4-tert-butylbenzoate 74.09
    morpholine 298.69
    tert-butylamine 259.21
    n-dodecanol 43.34
    dimethoxymethane 452.96
    ethylene carbonate 56.9
    cyrene 112.52
    2-ethoxyethyl acetate 51.51
    2-ethylhexyl acetate 28.99
    1,2,4-trichlorobenzene 27.02
    4-methylpyridine 78.13
    dibutyl ether 49.42
    2,6-dimethyl-4-heptanol 39.93
    DEF 177.4
    dimethyl isosorbide 129.42
    tetrachloroethylene 51.19
    eugenol 89.87
    triacetin 56.79
    span 80 85.25
    1,4-butanediol 166.56
    1,1-dichloroethane 64.32
    2-methyl-1-pentanol 107.64
    methyl formate 213.41
    2-methyl-1-butanol 175.82
    n-decane 14.73
    butyronitrile 96.67
    3,7-dimethyl-1-octanol 57.33
    1-chlorooctane 30.46
    1-chlorotetradecane 17.19
    n-nonane 14.66
    undecane 12.19
    tert-butylcyclohexane 16.89
    cyclooctane 10.6
    cyclopentanol 173.77
    tetrahydropyran 151.06
    tert-amyl methyl ether 156.85
    2,5,8-trioxanonane 173.82
    1-hexene 58.18
    2-isopropoxyethanol 198.77
    2,2,2-trifluoroethanol 125.24
    methyl butyrate 89.18

    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