Furfuryl alcohol is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. Th ...

containing a

furan Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen atom. Chemical compounds containing such rings are also referred to as furans. Furan is a colorless, flammable, highl ...

substituted with a hydroxymethyl group. It is a colorless liquid, but aged samples appear amber. It possesses a faint odor of burning and a bitter taste. It is

miscible Miscibility () is the property of two substances to mix in all proportions (that is, to fully dissolve in each other at any concentration), forming a homogeneous mixture (a solution). The term is most often applied to liquids but also applies ...

with but unstable in water. It is soluble in common

organic solvent A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...

Synthesis

Furfuryl alcohol is manufactured industrially by hydrogenation of

furfural Furfural is an organic compound with the formula C4H3OCHO. It is a colorless liquid, although commercial samples are often brown. It has an aldehyde group attached to the 2-position of furan. It is a product of the dehydration of sugars, as occur ...

, which is itself typically produced from waste bio-mass such as

corncob A corncob, also called corn cob, cob of corn or corn on the cob, is the central core of an ear of corn (also known as maize). It is the part of the ear on which the kernels grow. The ear is also considered a "cob" or "pole" but it is not ful ...

s or

sugar cane Sugarcane or sugar cane is a species of (often hybrid) tall, perennial grass (in the genus '' Saccharum'', tribe Andropogoneae) that is used for sugar production. The plants are 2–6 m (6–20 ft) tall with stout, jointed, fibrous stalk ...

bagasse Bagasse ( ) is the dry pulpy fibrous material that remains after crushing sugarcane or sorghum stalks to extract their juice. It is used as a biofuel for the production of heat, energy, and electricity, and in the manufacture of pulp and building ...

. As such furfuryl alcohol may be considered a green chemical. One-pot systems have been investigated to produce furfuryl alcohol directly from

xylose Xylose ( grc, ξύλον, , "wood") is a sugar first isolated from wood, and named for it. Xylose is classified as a monosaccharide of the aldopentose type, which means that it contains five carbon atoms and includes an aldehyde functional g ...

using

solid acid Solid is one of the four fundamental states of matter (the others being liquid, gas, and plasma). The molecules in a solid are closely packed together and contain the least amount of kinetic energy. A solid is characterized by structural ...

catalysts.

Reactions

It undergoes many reactions including Diels-Alder additions to electrophilic alkenes and alkynes. Hydroxymethylation gives 1,5-bis(hydroxymethyl)furan. Hydrolysis gives

levulinic acid Levulinic acid, or 4-oxopentanoic acid, is an organic compound with the formula CH3C(O)CH2CH2CO2H. It is classified as a keto acid. This white crystalline solid is soluble in water and polar organic solvents. It is derived from degradation of cel ...

. Upon treatment with acids, heat and/or

catalysts Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

, furfuryl alcohol can be made to polymerize into a resin, poly(furfuryl alcohol). Hydrogenation of furfuryl alcohol can proceed to give hydroxymethyl derivative of tetrahydrofuran and 1,5-pentanediol. The etherification reaction of furfuryl alcohol with alkyl or aryl halide (e.g. benzyl chloride) in the liquid-liquid-liquid triphase system with the help of a phase transfer catalyst also reported. In the Achmatowicz reaction, also known as the Achmatowicz rearrangement, furfuryl alcohol is converted to a dihydropyran.

Applications

Resins, composites

The primary use of furfuryl alcohol is as a

monomer In chemistry, a monomer ( ; '' mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification ...

for the synthesis of furan resins. These polymers are used in

thermoset polymer matrix A thermoset polymer matrix is a synthetic polymer reinforcement where polymers act as binder or matrix to secure in place incorporated particulates, fibres or other reinforcements. They were first developed for structural applications, such as gla ...

composites, cements,

adhesives Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advant ...

, coatings and casting/foundry resins. Polymerization involves an acid-catalyzed polycondensation, usually giving a black cross-linked product. A highly simplified representation is shown below. Furan resin

Because of its low molecular weight, furfuryl alcohol can impregnate the cells of wood, where it can be polymerized and bonded with the wood by heat, radiation, and/or catalysts or additional reactants. The treated wood (e.g. " Kebony") has improved moisture-dimensional stability, hardness, and decay and insect resistance; catalysts can include

zinc chloride Zinc chloride is the name of inorganic chemical compounds with the formula ZnCl2 and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white, and are highly soluble in water. This salt is hygroscopic ...

, citric, and

formic acid Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Est ...

, as well as borates.

Use as rocket propellant (fuel component)

Furfuryl alcohol has been used in rocketry as a fuel which ignites

hypergolic A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. T ...

ally (immediately and energetically in contact) with

white fuming nitric acid Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nit ...

red fuming nitric acid Red fuming nitric acid (RFNA) is a storable oxidizer used as a rocket propellant. It consists of 84% nitric acid (), 13% dinitrogen tetroxide and 1–2% water. The color of red fuming nitric acid is due to the dinitrogen tetroxide, which breaks ...

oxidizer. The use of hypergolics avoids the need for an

igniter In pyrotechnics, a pyrotechnic initiator (also initiator or igniter) is a device containing a pyrotechnic composition used primarily to ignite other, more difficult-to-ignite materials, such as thermites, gas generators, and solid-fuel rockets. T ...

. In late 2012, Spectra, a concept liquid rocket engine using white fuming nitric acid as the oxidizer to furfuryl alcohol fuel was static tested by

Copenhagen Suborbitals Copenhagen Suborbitals is an amateur, crowd-funded, and open-source human space program. Since its beginning in 2008, Copenhagen Suborbitals has flown five home-built rockets and two mock-up space capsules. Their stated goal is to have one of th ...

Safety

The

median lethal dose In toxicology, the median lethal dose, LD50 (abbreviation for " lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is ...

for furfuryl alcohol ranges from 160 to 400 mg/kg (mouse or rabbit, oral).

References

External links

Health hazards

*Literature

{{Authority control 2-Furyl compounds Hydroxymethyl compounds Rocket fuels Alcohol solvents