Quick Search
Maleic anhydride is an organic compound with the chemical formula C4H203.
Maleic anhydride is the acid anhydride of maleic acid and in its pure state Maleic anhydride is a colourless or white solid with an acrid odour.
Maleic anhydride is truly a remarkable molecule in that it possesses two types of chemical functionality making it uniquely useful in chemical synthesis and applications.
CAS: 108-31-6
MF: C4H2O3
MW: 98.06
EINECS: 203-571-6
Maleic anhydride is a multifunctional chemical intermediate with applications in several fields of chemical industry.
Maleic anhydride's major end use is as feedstock in the production of unsaturated polyester resins (UPR).
These resins are used both in glass-reinforced and in unreinforced applications.
The UPR end uses includes a wide range of applications in construction, marine and automobile industries.
In addition, Maleic anhydride can also be used as raw material in the production of 1,4-butanediol (BDO), gamma- butyrolactone and tetrahydrofuran (THF).
Maleic anhydride is important to highlight that BDO is one of the world's fastest growing chemicals in the last years.
Maleic anhydride is a cyclic dicarboxylic anhydride that is the cyclic anhydride of maleic acid.
Maleic anhydride has a role as an allergen.
Maleic anhydride is a cyclic dicarboxylic anhydride and a member of furans.
Colorless crystalline needles, flakes, pellets, rods, briquettes, lumps or a fused mass.
Melts at 113°F.
Shipped both as a solid and in the molten state.
Vapors, fumes and dusts strong irritate the eyes, skin and mucous membranes.
Flash point 218°F.
Autoignition temperature 890°F.
Used to make paints and plastics and other chemicals.
Maleic anhydride is an organic compound with the formula C2H2(CO)2O.
Maleic anhydride is the acid anhydride of maleic acid.
Maleic anhydride is a colorless or white solid with an acrid odor.
Maleic anhydride is produced industrially on a large scale for applications in coatings and polymers.
Maleic anhydride is used in the preparation of unsaturated polyester resins, 4-butanediol, fumairc acid, tetrahydrofuran and gamma-butyrolactone.
Maleic anhydride is also used as lubricating oil additives, dispersants, artificial sweeteners, flavor enhancements, floor polishes and corrosion inhibitors.
Maleic anhydride finds application in personal care products like hair sprays.
Further, Maleic anhydride is used in water treatment chemicals, detergents, pharmaceuticals and copolymers.
Maleic anhydride is an active substrate for Diels-Alder reactions and dimerizes to form cyclobutane tetracarboxylic dianhydride .
Maleic anhydride Chemical Properties
Melting point: 51-56 °C (lit.)
Boiling point: 200 °C (lit.)
Density: 1.48
Vapor density: 3.4 (vs air)
Vapor pressure: 0.16 mm Hg ( 20 °C)
Refractive index: 1.4688 (estimate)
Fp: 218 °F
Storage temp.: Store below +30°C.
Form: powder
pka: 0[at 20 ℃]
Color: White
PH: 0.8 (550g/l, H2O, 20℃)Hydrolysis
Explosive limit: 1.4-7.1%(V)
Water Solubility: 79 g/100 mL (25 ºC)
Sensitive: Moisture Sensitive
Merck: 14,5704
BRN: 106909
Henry's Law Constant: (atm m3/mol): Not applicable - reacts with water
Exposure limits NIOSH REL: TWA 1 ppm (0.25 mg/m3), IDLH 10 ppm; OSHA PEL: TWA 0.25 ppm; ACGIH TLV: TWA 0.25 ppm with an intended change of 0.1 ppm.
Stability: Stable. Combustible. Incompatible with water, strong oxidizing agents, alkali metals, strong bases, amines, most common metals, polymerization catalysts and accelerators.
InChIKey: FPYJFEHAWHCUMM-UHFFFAOYSA-N
LogP: -2.61 at 20℃
CAS DataBase Reference: 108-31-6(CAS DataBase Reference)
NIST Chemistry Reference: Maleic anhydride (108-31-6)
EPA Substance Registry System: Maleic anhydride (108-31-6)
Maleic anhydride is colorless needles, white lumps, or pellets.
Irritating, choking odor.
Dissolves in water to produce maleic acid.
Dissolves in ethanol and produces esters.
White, hydroscopic crystals (usually shipped as briquettes).
Odor threshold concentration is 0.32 ppm (quoted, Amoore and Hautala, 1983).
Uses
In the manufacture of polyester resins, fumaric acid, agricultural pesticides, and alkyl resins.
Maleic anhydride is heterocyclic compound used in the manufacture of unsaturated polyester resins.
Maleic anhydride has a wide range of other applications; it is used in synthetic tensides, insecticides, herbicides and fungicides.
In Diels-Alder syntheses (as a dienophile), manufacture of alkyd-type of resins, dye intermediates, pharmaceuticals, agricultural chemicals (maleic hydrazide, malathion), in copolymerization reactions.
Plastics & resins
Around 50% of world maleic anhydride output is used in the manufacture of unsaturated polyester resins (UPR).
Chopped glass fibers are added to UPR to produce fiberglass reinforced plastics that are used in a wide range of applications such as pleasure boats, bathroom fixtures, automobiles, tanks and pipes.
Maleic anhydride is hydrogenated to 1,4-butanediol (BDO), used in the production of thermoplastic polyurethanes, elastane/Spandex fibers, polybutylene terephthalate (PBT) resins and many other products.
Curing agents
Diels-Alder reaction of maleic anhydride and butadiene and isoprene gives the respective tetrahydrophthalic anhydrides which can be hydrogenated to the corresponding hexahydrophthalic anhydrides.
These species are used as curing agents in epoxy resins.
Another market for maleic anhydride is lubricating oil additives, which are used in gasoline and diesel engine crankcase oils as dispersants and corrosion inhibitors.
Changes in lubricant specifications and more efficient engines have had a negative effect on the demand for lubricating oil additives, giving flat growth prospects for maleic anhydride in this application.
Others
A number of smaller applications for maleic anhydride.
The food industry uses malic acid which is derivative of Maleic anhydride in artificial sweeteners and flavour enhancements.
Personal care products consuming Maleic anhydride include hair sprays, adhesives and floor polishes.
Maleic anhydride is also a precursor to compounds used for water treatment detergents, insecticides and fungicides, pharmaceuticals, and other copolymers.
Production Methods
Maleic anhydride is produced by vapor-phase oxidation of n-butane.
The overall process converts the methyl groups to carboxylate and dehydrogenates the backbone. The selectivity of the process reflects the robustness of maleic anhydride, with its conjugated double-bond system.
Traditionally Maleic anhydride was produced by the oxidation of benzene or other aromatic compounds.
As of 2006, only a few smaller plants continue to use benzene.
In both cases, benzene and butane are fed into a stream of hot air, and the mixture is passed through a catalyst bed at high temperature.
The ratio of air to hydrocarbon is controlled to prevent the mixture from igniting.
Vanadium pentoxide and molybdenum trioxide are the catalysts used for the benzene route, whereas vanadium phosphate is used for the butane route:
C4H10 + 3.5 O2 → C4H2O3 + 4 H2O ∆H = −1236 kJ/mol
The main competing process entails full combustion of the butane, a conversion that is twice as exothermic as the partial oxidation.
The traditional method using benzene became uneconomical due to the high and still rising benzene prices and by complying with the regulations of benzene emissions.
In addition, in the production of maleic anhydride (4 C-atoms) a third of the original carbon atoms is lost as carbon dioxide when using benzene (6 carbon atoms).
The modern catalytic processes start from a 4-carbon molecule and only attaches oxygen and removes water; the 4-C-base body of the molecule remains intact.
Overall, the newer method is therefore more material efficient.
Parallels exist with the production of phthalic anhydride: While older methods use naphthalene, modern methods use o-xylene as feedstock.
Preparation
To a flask equipped with a Dean-Stark trap, condenser, and mechanical stirrer is added 116 gm (1.0 mole) of maleic acid and 120 ml of tetrachloroethane.
The contents are heated, the water (18 ml, 1.0 mole) distilled off as the azeotrope, and the residue distilled under reduced pressure to afford 87.7 gm (89.5%) of the anhydride, b.p. 82-84°C (15 mm), m.p. 53°C.
The residue remaining in the flask consists of about 10 gm of fumaric acid, m.p. 287°C.
Fumaric and maleic acids both give maleic anhydride on heating.
Fumaric acid must first be heated to a higher temperature to effect its conversion to maleic acid prior to its dehydration.
Reactions
The chemistry of maleic anhydride is very rich, reflecting its ready availability and bifunctional reactivity.
Maleic anhydride hydrolyzes, producing maleic acid, cis-HOOC–CH=CH–COOH.
With alcohols, the half-ester is generated, e.g., cis-HOOC–CH=CH–COOCH3.
Maleic anhydride is a classic substrate for Diels-Alder reactions.
Maleic anhydride was used for work in 1928, on the reaction between maleic anhydride and 1,3-butadiene, for which Otto Paul Hermann Diels and Kurt Alder were awarded the Nobel Prize in 1950.
Maleic anhydride is through this reaction that maleic anhydride converted to many pesticides and pharmaceuticals.
Their 1928 patent also provided many other examples of reactions involving Maleic anhydride, such as the reaction with cyclopentadiene to form nadic anhydride.
Michael reaction of Maleic anhydride with active methylene or methine compounds such as malonate or acetoacetate esters in the presence of sodium acetate catalyst.
These intermediates were subsequently used for the generation of the Krebs cycle intermediates aconitic and isocitric acids.
Maleic anhydride dimerizes in a photochemical reaction to form cyclobutane tetracarboxylic dianhydride (CBTA).
Maleic anhydride is used in the production of polyimides and as an alignment film for liquid crystal displays.
Maleic anhydride is also a ligand for low-valent metal complexes, examples being Pt(PPh3)2(MA) and Fe(CO)4(MA).
On account of its cycle of 4 π electrons in an array of 5 atoms with p orbitals, Maleic anhydride was long thought to exhibit antiaromaticity.
However, a thermochemical study concluded that only 8 kJ/mol of destabilization energy can be ascribed to this effect, making it weakly antiaromatic at best.
Health Hazard
Irritant to tissue.
Dermal and respiratory sensitization.
Questionable carcinogen.
Inhalation causes coughing, sneezing, throat irritation.
Skin contact causes irritation and redness.
Vapors cause severe eye irritation; photophobia and double vision may occur.
Behavior in Fire: When heated above 300°F in the presence of various materials may generate heat and carbon dioxide.
Will explode if confined.
Toxicity evaluation
Maleic anhydride was described as having anticarcinogenic properties, and some of the maleic copolymers can have biologic activity by themselves, especially antitumor activity.
Information related to this compound is contradictory.
Chromosomal aberrations in cultured hamster cells but no mutagenicity in in vitro tests in bacteria have been reported.
No effects on cholinesterase activity have been described after exposure to maleic anhydride.
Reacts slowly with water (hydrolyzes) to form maleic acid, a medium-strong acid.
Dust may form explosive mixture with air.
Reacts with strong oxidizers, oil, water, alkali metals; strong acids; strong bases.
Violent reaction with alkali metals and amines above 66 C.
Dangerous reaction with oxidizers, amines, alkali metals, and hydroxides.
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).
Food and Beverage
Another common use of maleic anhydride is in food and beverage.
Maleic anhydride is approved by the Food and Drug Administration (FDA) for use as an ''indirect'' food additive.
Specifically in this application, maleic anhydride can be converted back to maleic acid and/or fumaric acid, which can be used in the production of food additives.
Food additives containing maleic anhydride can serve as a preservative, control pH, or enhance flavor in foods and beverages.
Maleic anhydride can provide a puckering, sour flavor to food products and is commonly added to pudding mixes and powdered drinks to enhance flavor.
Synonyms
MALEIC ANHYDRIDE
2,5-Furandione
108-31-6
furan-2,5-dione
Toxilic anhydride
Maleic acid anhydride
cis-Butenedioic anhydride
Dihydro-2,5-dioxofuran
2,5-dihydrofuran-2,5-dione
Maleinanhydrid
RCRA waste number U147
MALEICANHYDRIDE
NSC 137651
Anhydrid kyseliny maleinove
CHEBI:474859
24937-72-2
184288-31-1
V5877ZJZ25
NSC-137651
Maleic Anhydrides
Maleinanhydrid [Czech]
2,5-Furanedione
CCRIS 2941
HSDB 183
Anhydrid kyseliny maleinove [Czech]
EINECS 203-571-6
UN2215
RCRA waste no. U147
BRN 0106909
UNII-V5877ZJZ25
AI3-24283
fumaric anhydride
furan-2,5-quinone
MFCD00005518
68261-15-4
Maleic anhydride, 99%
Maleic Anhydride (MAN)
Epitope ID:122673
EC 203-571-6
Lytron 810 (Salt/Mix)
Lytron 820 (Salt/Mix)
Maleic anhydride, briquettes
Maleic anhydride (briquette)
Maleic anhydride treated BSA
Maleic anhydride-1-[13C]
5-17-11-00055 (Beilstein Handbook Reference)
MALEIC ANHYDRIDE [MI]
(Z)-butanedioic acid anhydride
BDBM7812
CHEMBL374159
MALEIC ANHYDRIDE [HSDB]
MALEIC ANHYDRIDE [INCI]
DTXSID7024166
Maleic anhydride, powder, 95%
NSC9568
CS-Z0016
NSC-9568
ZINC8100874
Tox21_200406
NSC137651
NSC137652
NSC137653
STL197476
AKOS000121041
NSC-137652
NSC-137653
UN 2215
NCGC00248595-01
NCGC00257960-01
BP-20394
CAS-108-31-6
Maleic anhydride, for synthesis, 99.0%
Maleic anhydride [UN2215] [Corrosive]
FT-0628122
FT-0670909
FT-0693473
M 188
M0005
EN300-17997
Maleic anhydride, puriss., >=99.0% (NT)
Maleic anhydride, SAJ first grade, >=98.0%
A801842
Q412377
J-002092
J-521668
F0001-0164
Maleic anhydride, 95% (may contain up to 5% maleic acid)
