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. The ...
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, highly ...
substituted with a
hydroxymethyl
The hydroxymethyl group is the name for a substituent with the structural formula −CH2−OH. It consists of a methylene bridge (−CH2− unit) bonded to a hydroxyl group (−OH). This makes the hydroxymethyl group an alcohol. It has the identic ...
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 p ...
s.
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 occurs ...
, 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 fully ...
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 stalks t ...
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 gro ...
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 ri ...
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 cell ...
. 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
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many for ...
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
In chemistry, a phase-transfer catalyst or PTC is a catalyst that facilitates the transition of a reactant from one phase into another phase where reaction occurs. Phase-transfer catalysis is a special form of heterogeneous catalysis. Ionic reac ...
also reported. In the
Achmatowicz reaction
The Achmatowicz reaction, also known as the Achmatowicz rearrangement, is an organic synthesis in which a furan is converted to a dihydropyran. In the original publication by the Polish Chemist Osman Achmatowicz Jr. (b. 20 December 1931 in Vilniu ...
, also known as the Achmatowicz rearrangement, furfuryl alcohol is converted to a
dihydropyran In organic chemistry, dihydropyran refers to two heterocyclic compounds with the chemical formula, formula C5H8O:
*3,4-Dihydropyran, 3,4-Dihydro-2''H''-pyran
*3,6-dihydro-2''H''-pyran
Nomenclature
In IUPAC names, "dihydro" refers to the two adde ...
.
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
Mo ...
for the synthesis of
furan resin
Furan resin refers to polymers produced from various furan compounds, of which the most common starting materials are furfuryl alcohol and furfural. In the resin and in the cured polyfurfurol, the furan rings are not connected by conjugation. Th ...
s.
[ 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
In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on natu ...
. Polymerization involves an acid-catalyzed polycondensation, usually giving a black cross-linked product. A highly simplified representation is shown below.
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
Kebony is a Norwegian wood producer. The company has its roots in Wood Polymer Technologies (WPT), which was founded in 1996 and changed its name to Kebony in 2007. Kebony has a factory in Skien (Norway) and offices in Oslo (Norway).
Technology
...
") 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 and ev ...
, 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. Es ...
, 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. The ...
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 nitric ...
or 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. The ...
. 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 the ...
for furfuryl alcohol ranges from 160 to 400 mg/kg (mouse or rabbit, oral).
See also
*Furfurylamine
Furfurylamine is an aromatic amine typically formed by the reductive amination of furfural with ammonia.
The pharmaceutical drug furtrethonium, a parasympathomimetic cholinergic, is a trimethyl ammonium derivative of furfurylamine.
Furfurylam ...
- corresponding amine
*2-Furonitrile
2-Furonitrile is a colorless derivative of furan possessing a nitrile group.
Synthesis
Industrial synthesis is based on the vapor phase ammoxidation of furfural with ammonia over bismuth molybdate catalyst at 440-480 °C.
Numerous labora ...
- corresponding nitrile
*Furan-2-ylmethanethiol
Furan-2-ylmethanethiol (2-Furanmethanethiol) is an organic compound containing a furan substituted with a sulfanylmethyl group. It is a clear colourless liquid when pure, but it becomes yellow coloured upon prolonged standing. It possesses a stro ...
- corresponding thiol
* 2-Furoic acid - corresponding carboxylic acid
References
External links
Health hazards
*Literature
{{Authority control
2-Furyl compounds
Hydroxymethyl compounds
Rocket fuels
Alcohol solvents