Cashew nutshell liquid
Encyclopedia
The cashew nutshell liquid (CNSL) or cashew shell oil is a natural resin
found in the honeycomb structure of the cashew
nutshell
. It consists of about 90% anacardic acid
s and 10% cardol. Both substances are dermatogenic, like the oils of the poison ivy
, and present danger during manual cashew processing.
It is a raw material
of multiple uses in developing drugs, antioxidants, fungicides, etc. It is used in tropical folk medicine
and for anti-termite
treatment of timber
.
The anacardic acids have been used effectively in vivo against tooth abscess
es due to their lethality to gram-positive bacteria. They are also active against a wide range of other gram-positive bacteria. Many parts of the plant are used by the Patamona
of Guyana
medicinally. The bark is scraped and soaked overnight or boiled as an antidiarrheal. Seeds are ground up into powders used for antivenom for snake
bites. The nut oil is used topically as an antifungal
and for healing cracked heels.
Anacardic acid is also used in the chemical industry for the production of cardanol
, the recovery process of cardanol from CNSL can be obtained from thin film distillation
. This process also reduces the degree of thermal polymerization
of the un-saturated alkyl-phenols present in cashew shell nut liquid. This natural oil phenol has been found to have interesting chemical structural features which enable a range of chemical modifications to create a wide spectrum of bio-based monomers capitalising on the chemically versatile construct it containing three different functional groups, the aromatic ring, the hydroxyl group and the double bonds in the flanking alkyl chain. These can be split into key groups, there use as Polyols. Which have recently seen a dramatic increase in demand for their bio-based origin and key chemical attributes such as high reactivity, range of functionalities, reduction in blowing agents and naturally occurring fire retardant properties in the field of ridged polyurethanes aided by their inherent phenolic structure and larger number of reactive units per unit mass. CNSL based Novolac are another versatile industrial monomer deriving from cardanol typically used as reticulating agents for epoxy
matrices in composite
applications providing good thermal and mechanical properties to the final composite material. Further examples of applications which are Cashew shell nut liquid derived materials are being evaluated are in the fields of chemical intermediates, additives, stabilizers, lubricants, diesel engine fuel alternatives, poor point dispersants, anti-oxidants, anticorrosive paints. Abrasives and friction dusts have also been developed from Residol, the residue byproduct of this synthesis process.
During World War II it was used as a sabotage device by SOE (Special Operations Executive) for destroying the engines of German vehicles when poured into the crankcase of engines.
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
found in the honeycomb structure of the cashew
Cashew
The cashew is a tree in the family Anacardiaceae. Its English name derives from the Portuguese name for the fruit of the cashew tree, caju, which in turn derives from the indigenous Tupi name, acajú. It is now widely grown in tropical climates for its cashew nuts and cashew apples.-Etymology:The...
nutshell
Nutshell
A nutshell is the outer shell of a nut. Most nutshells are inedible and are removed before eating the nut meat inside.-Usage:Most nutshells are useful to some extent, depending on the circumstances...
. It consists of about 90% anacardic acid
Anacardic acid
Anacardic acids are chemical compounds found in the shell of the cashew nut . As they are closely related to urushiol, they also cause an allergic skin rash on contact, known as urushiol-induced contact dermatitis. Anacardic acid is a yellow liquid. It is miscible partially in alcohol and ether,...
s and 10% cardol. Both substances are dermatogenic, like the oils of the poison ivy
Poison ivy
Toxicodendron radicans, better known as poison ivy , is a poisonous North American plant that is well known for its production of urushiol, a clear liquid compound found within the sap of the plant that causes an itching rash in most people who touch it...
, and present danger during manual cashew processing.
It is a raw material
Raw material
A raw material or feedstock is the basic material from which a product is manufactured or made, frequently used with an extended meaning. For example, the term is used to denote material that came from nature and is in an unprocessed or minimally processed state. Latex, iron ore, logs, and crude...
of multiple uses in developing drugs, antioxidants, fungicides, etc. It is used in tropical folk medicine
Folk medicine
-Description:Refers to healing practices and ideas of body physiology and health preservation known to a limited segment of the population in a culture, transmitted informally as general knowledge, and practiced or applied by anyone in the culture having prior experience.All cultures and societies...
and for anti-termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
treatment of timber
Timber
Timber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...
.
The anacardic acids have been used effectively in vivo against tooth abscess
Tooth abscess
A tooth abscess or root abscess is pus enclosed in the tissues of the jaw bone at the apex of an infected tooth's root. Usually the abscess originates from a bacterial infection that has accumulated in the soft, often dead, pulp of the tooth. This can be caused by untreated tooth decay, cracked...
es due to their lethality to gram-positive bacteria. They are also active against a wide range of other gram-positive bacteria. Many parts of the plant are used by the Patamona
Patamona
The Patamona are an Amerindian group, known archaeologically from pottery collections in the Yawong Valley and the upper Siparuni River in the Pakaraima Mountains of Guyana. The upper Siparuni was exploited until recently for suitable farm lands, hunting and fishing...
of Guyana
Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...
medicinally. The bark is scraped and soaked overnight or boiled as an antidiarrheal. Seeds are ground up into powders used for antivenom for snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
bites. The nut oil is used topically as an antifungal
Antifungal
* Antifungal medication, a medication used to treat fungal infection s such as athlete's foot , ringworm, candidiasis, etc.* Antifungal protein, a protein family* an adjective referring to a fungicide compound...
and for healing cracked heels.
Anacardic acid is also used in the chemical industry for the production of cardanol
Cardanol
Cardanol is a phenol obtained from anacardic acid, the main component of cashew nutshell liquid , a byproduct of cashew nut processing. Cardanol finds use in the chemical industry in resins, coatings, frictional materials, and surfactants used as pigment dispersants for water-based inks...
, the recovery process of cardanol from CNSL can be obtained from thin film distillation
Distillation
Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....
. This process also reduces the degree of thermal polymerization
Polymerization
In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...
of the un-saturated alkyl-phenols present in cashew shell nut liquid. This natural oil phenol has been found to have interesting chemical structural features which enable a range of chemical modifications to create a wide spectrum of bio-based monomers capitalising on the chemically versatile construct it containing three different functional groups, the aromatic ring, the hydroxyl group and the double bonds in the flanking alkyl chain. These can be split into key groups, there use as Polyols. Which have recently seen a dramatic increase in demand for their bio-based origin and key chemical attributes such as high reactivity, range of functionalities, reduction in blowing agents and naturally occurring fire retardant properties in the field of ridged polyurethanes aided by their inherent phenolic structure and larger number of reactive units per unit mass. CNSL based Novolac are another versatile industrial monomer deriving from cardanol typically used as reticulating agents for epoxy
Epoxy
Epoxy, also known as polyepoxide, is a thermosetting polymer formed from reaction of an epoxide "resin" with polyamine "hardener". Epoxy has a wide range of applications, including fiber-reinforced plastic materials and general purpose adhesives....
matrices in composite
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
applications providing good thermal and mechanical properties to the final composite material. Further examples of applications which are Cashew shell nut liquid derived materials are being evaluated are in the fields of chemical intermediates, additives, stabilizers, lubricants, diesel engine fuel alternatives, poor point dispersants, anti-oxidants, anticorrosive paints. Abrasives and friction dusts have also been developed from Residol, the residue byproduct of this synthesis process.
During World War II it was used as a sabotage device by SOE (Special Operations Executive) for destroying the engines of German vehicles when poured into the crankcase of engines.