Resin

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.[1] Resins are usually mixtures of organic compounds. This article focuses on naturally-occurring resins.

Plants secrete resins for their protective benefits in response to injury. The resin protects the plant from insects and pathogens.[2] Resins confound a wide range of herbivores, insects, and pathogens, while the volatile phenolic compounds may attract benefactors such as parasitoids or predators of the herbivores that attack the plant.[3]

Cedar of Lebanon cone
Cedar of Lebanon cone showing flecks of resin as used in the mummification of Egyptian Pharaohs.
Resin with insect (aka)
Insect trapped in resin

Composition

Most plant resins are composed of terpenes. Specific components are alpha-pinene, beta-pinene, delta-3 carene, and sabinene, the monocyclic terpenes limonene and terpinolene, and smaller amounts of the tricyclic sesquiterpenes, longifolene, caryophyllene, and delta-cadinene. Some resins also contain a high proportion of resin acids. Rosins on the other hand are less volatile and consist, inter alia, of diterpenes.

Examples

Notable examples of plant resins include amber, Balm of Gilead, balsam, Canada balsam, Boswellia, copal from trees of Protium copal and Hymenaea courbaril, dammar gum from trees of the family Dipterocarpaceae, Dragon's blood from the dragon trees (Dracaena species), elemi, frankincense from Boswellia sacra, galbanum from Ferula gummosa, gum guaiacum from the lignum vitae trees of the genus Guaiacum, kauri gum from trees of Agathis australis, hashish (Cannabis resin) from Cannabis indica, labdanum from mediterranean species of Cistus, mastic (plant resin) from the mastic tree Pistacia lentiscus, myrrh from shrubs of Commiphora, sandarac resin from Tetraclinis articulata, the national tree of Malta, styrax (a Benzoin resin from various Styrax species), spinifex resin from Australian grasses, and turpentine, distilled from pine resin.

Amber is fossil resin (also called resinite) from coniferous and other tree species. Copal, kauri gum, dammar and other resins may also be found as subfossil deposits. Subfossil copal can be distinguished from genuine fossil amber because it becomes tacky when a drop of a solvent such as acetone or chloroform is placed on it.[4] African copal and the kauri gum of New Zealand are also procured in a semi-fossil condition.

Rosin

Araucaria Resin
Extremely viscous resin extruding from the trunk of a mature Araucaria columnaris.

Solidified resin from which the volatile terpenes have been removed by distillation is known as rosin. Typical rosin is a transparent or translucent mass, with a vitreous fracture and a faintly yellow or brown colour, non-odorous or having only a slight turpentine odor and taste. Rosin is insoluble in water, mostly soluble in alcohol, essential oils, ether, and hot fatty oils. Rosin softens and melts under the influence of heat. Rosin burns with a bright but smoky flame.

Rosin consists of a complex mixture of different substances including organic acids named the resin acids. Related to the terpenes, resin acid are oxidized terpenes. Resin acids dissolved in alkalis to form resin soaps, from which the purified resin acids are regenerated upon treatment with acids. Examples of resin acids are abietic acid (sylvic acid), C20H30O2, plicatic acid contained in cedar, and pimaric acid, C20H30O2, a constituent of galipot resin. Abietic acid can also be extracted from rosin by means of hot alcohol. Pimaric acid closely resembles abietic acid into which it passes when distilled in a vacuum; it has been supposed to consist of three isomers.

Rosin is obtained from pines and some other plants, mostly conifers.[5] Plant resins are generally produced as stem secretions, but in some Central and South American species such as Euphorbia dalechampia and Clusia species they are produced as pollination rewards, and used by some stingless bee species to construct their nests.[6][7] Propolis, consisting largely of resins collected from plants such as poplars and conifers, is used by honey bees to seal small gaps in their hives, while larger gaps are filled with beeswax.[8]

Petroleum- and insect-derived resins

Shellac and lacquer are examples of insect-derived resins.

Asphaltite and Utah resin are petroleum bitumens, not a product secreted by plants, although it was ultimately derived from plants.

History and etymology

Resin on Almond tree
Resin dripping from an almond tree

Human use of plant resins has a very long history that was documented in ancient Greece by Theophrastus, in ancient Rome by Pliny the Elder, and especially in the resins known as frankincense and myrrh, prized in ancient Egypt.[9] These were highly prized substances, and required as incense in some religious rites.

The word resin comes from French resine, from Latin resina "resin", which either derives from or is a cognate of the Greek ῥητίνη rhētinē "resin of the pine", of unknown earlier origin, though probably non-Indo-European.[10][11]

The word "resin" has been applied in the modern world to nearly any component of a liquid that will set into a hard lacquer or enamel-like finish. An example is nail polish. Certain "casting resins" and synthetic resins (such as epoxy resin) have also been given the name "resin."

Some resins when soft are known as 'oleoresins', and when containing benzoic acid or cinnamic acid they are called balsams. Oleoresins are naturally occurring mixtures of an oil and a resin; they can be extracted from various plants. Other resinous products in their natural condition are a mix with gum or mucilaginous substances and known as gum resins. Several natural resins are used as ingredients in perfumes, e.g., balsams of Peru and tolu, elemi, styrax, and certain turpentines.[5]

Non-resinous exudates

Other liquid compounds found inside plants or exuded by plants, such as sap, latex, or mucilage, are sometimes confused with resin but are not the same. Saps, in particular, serve a nutritive function that resins do not.

Résine
Resin of a pine

Uses

Plant resins

Plant resins are valued for the production of varnishes, adhesives, and food glazing agents. They are also prized as raw materials for the synthesis of other organic compounds and provide constituents of incense and perfume. The oldest known use of plant resin comes from the late Middle Stone Age in Southern Africa where it was used as an adhesive for hafting stone tools.[12]

Frankincense 2005-12-31
Lumps of dried frankincense resin
Protium Sp. MHNT.BOT.2016.24.54
Protium Sp. - MHNT

The hard transparent resins, such as the copals, dammars, mastic, and sandarac, are principally used for varnishes and adhesives, while the softer odoriferous oleo-resins (frankincense, elemi, turpentine, copaiba), and gum resins containing essential oils (ammoniacum, asafoetida, gamboge, myrrh, and scammony) are more used for therapeutic purposes, food and incense. The resin of the Aleppo Pine is used to flavour retsina, a Greek resinated wine.[13]

Synthetic resins

Many materials are produced via the conversion of synthetic resins to solids. Important examples are bisphenol A diglycidyl ether, which is a resin converted to epoxy glue upon the addition of a hardener. Silicones are often prepared from silicone resins via room temperature vulcanization.

See also

References

  1. ^ Chemistry, International Union of Pure and Applied. IUPAC Compendium of Chemical Terminology. iupac.org. IUPAC. doi:10.1351/goldbook.RT07166.
  2. ^ "Resins". www.fs.fed.us.
  3. ^ "Plant Resins: Chemistry, evolution, ecology, and ethnobotany", by Jean Langenheim, Timber Press, Portland, OR. 2003
  4. ^ David Grimaldi, Amber: Window to the Past, 1996, p 16-20, American Museum of Natural History
  5. ^ a b Fiebach, Klemens; Grimm, Dieter (2000). "Resins, Natural". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a23_073. ISBN 978-3-527-30673-2.
  6. ^ Bittrich, V.; Amaral, Maria C. E. (1996). "Flower morphology and pollination biology of some Clusia species from the Gran Sabana (Venezuela)". Kew Bulletin. 51 (4): 681–694. doi:10.2307/4119722. JSTOR 4119722.
  7. ^ Gonçalves-Alvim, Silmary de Jesus (2001). "Resin-collecting bees (Apidae) on Clusia palmicida (Clusiaceae) in a riparian forest in Brazil". Journal of Tropical Ecology. 17 (1): 149–153. doi:10.1017/s0266467401001092.
  8. ^ Simone-Finstrom, M.; Spivak, M. (2010). "Propolis and bee health: The natural history and significance of resin use by honey bees" (PDF). Apidologie. 41 (3): 295–311. doi:10.1051/apido/2010016.
  9. ^ "Queen Hatshepsut's expedition to the Land of Punt: The first oceanographic cruise?". Dept. of Oceanography, Texas A&M University. Retrieved 2010-05-08.
  10. ^ "resin, n. and adj". OED Online. Oxford University Press. September 2014. Retrieved 2 December 2014.
  11. ^ "resin (n.)". Online Etymology Dictionary. Retrieved 2 December 2014.
  12. ^ Kozowyk, P. R. B.; Langejans, G. H. J.; Poulis, J. A. (2016-03-16). "Lap Shear and Impact Testing of Ochre and Beeswax in Experimental Middle Stone Age Compound Adhesives". PLOS ONE. 11 (3): e0150436. doi:10.1371/journal.pone.0150436. ISSN 1932-6203.
  13. ^ "Non-wood forest products from conifers - CHAPTER 6". www.fao.org.

External links

  • The dictionary definition of resin at Wiktionary
  • Media related to Resin at Wikimedia Commons
Acrylonitrile butadiene styrene

Acrylonitrile butadiene styrene (ABS) (chemical formula (C8H8)x·​(C4H6)y·​(C3H3N)z) is a common thermoplastic polymer. Its glass transition temperature is approximately 105 °C (221 °F). ABS is amorphous and therefore has no true melting point.

ABS is a terpolymer made by polymerizing styrene and acrylonitrile in the presence of polybutadiene. The proportions can vary from 15 to 35% acrylonitrile, 5 to 30% butadiene and 40 to 60% styrene. The result is a long chain of polybutadiene criss-crossed with shorter chains of poly(styrene-co-acrylonitrile). The nitrile groups from neighboring chains, being polar, attract each other and bind the chains together, making ABS stronger than pure polystyrene. The styrene gives the plastic a shiny, impervious surface. The polybutadiene, a rubbery substance, provides toughness even at low temperatures. For the majority of applications, ABS can be used between −20 and 80 °C (−4 and 176 °F) as its mechanical properties vary with temperature. The properties are created by rubber toughening, where fine particles of elastomer are distributed throughout the rigid matrix.

Agathis

Agathis, commonly known as kauri or dammara, is a genus of 22 species of evergreen tree. The genus is part of the ancient conifer family Araucariaceae, a group once widespread during the Jurassic and Cretaceous periods, but now largely restricted to the Southern Hemisphere except for a number of extant Malesian Agathis.

Amber

Amber is fossilized tree resin, which has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects. Amber is used in jewelry. It has also been used as a healing agent in folk medicine.

There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material as inclusions. Amber occurring in coal seams is also called resinite, and the term ambrite is applied to that found specifically within New Zealand coal seams.

Benzoin (resin)

Benzoin or benjamin (corrupted pronunciation) is a balsamic resin obtained from the bark of several species of trees in the genus Styrax. It is used in perfumes, some kinds of incense, as a flavoring, and medicine (see tincture of benzoin). It is distinct from the chemical compound benzoin, which is ultimately derived from benzoin resin; the resin, however, does not contain this compound.

Benzoin is sometimes called gum benzoin or gum benjamin, and in India as loban, though loban is, via Arabic lubān, a generic term for frankincense-type incense, e.g., fragrant tree resin. Benzoin is also called storax, not to be confused with the balsam of the same name obtained from the Hamamelidaceae family.

Benzoin is a common ingredient in incense-making and perfumery because of its sweet vanilla-like aroma and fixative properties. Gum benzoin is a major component of the type of church incense used in Russia and some other Orthodox Christian societies, as well as Western Catholic Churches. Most benzoin is used in the Arab states of the Persian Gulf and India, where it is burned on charcoal as an incense. It is also used in the production of Bakhoor (Arabic بخور - scented wood chips) as well as various mixed resin incense in the Arab countries and the Horn of Africa. Benzoin is also used in blended types of Japanese incense, Indian incense, Chinese incense (known as Anxi xiang; 安息香), and Papier d'Arménie as well as incense sticks.

There are two common kinds of benzoin, benzoin Siam and benzoin Sumatra. Benzoin Siam is obtained from Styrax tonkinensis, found across Thailand, Laos, Cambodia, and Vietnam. Benzoin Sumatra is obtained from Styrax benzoin, which grows predominantly on the island of Sumatra. Unlike Siamese benzoin, Sumatran benzoin contains cinnamic acid in addition to benzoic acid. In the United States, Sumatra benzoin (Styrax benzoin and Styrax paralleoneurus) is more customarily used in pharmaceutical preparations, Siam benzoin (Styrax tonkinensis et al.) in the flavor and fragrance industries.In perfumery, benzoin is used as a fixative, slowing the dispersion of essential oils and other fragrance materials into the air. Benzoin is used in cosmetics, veterinary medicine, and scented candles. It is used as a flavoring in alcoholic and nonalcoholic beverages, baked goods, chewing gum, frozen dairy, gelatins, puddings, and soft candy.

Composite material

A composite material (also called a composition material or shortened to composite, which is the common name) is a material made from two or more constituent materials with significantly different physical or chemical properties that, when combined, produce a material with characteristics different from the individual components. The individual components remain separate and distinct within the finished structure, differentiating composites from mixtures and solid solutions.The new material may be preferred for many reasons. Common examples include materials which are stronger, lighter, or less expensive when compared to traditional materials.

More recently, researchers have also begun to actively include sensing, actuation, computation and communication into composites, which are known as Robotic Materials.Typical engineered composite materials include:

Reinforced concrete and masonry

Composite wood such as plywood

Reinforced plastics, such as fibre-reinforced polymer or fiberglass

Ceramic matrix composites (composite ceramic and metal matrices)

Metal matrix composites

and other Advanced composite materialsComposite materials are generally used for buildings, bridges, and structures such as boat hulls, swimming pool panels, racing car bodies, shower stalls, bathtubs, storage tanks, imitation granite and cultured marble sinks and countertops.

The most advanced examples perform routinely on spacecraft and aircraft in demanding environments.

Epoxy

Epoxy is either any of the basic components or the cured end products of epoxy resins, as well as a colloquial name for the epoxide functional group. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups.

Epoxy resins may be reacted (cross-linked) either with themselves through catalytic homopolymerisation, or with a wide range of co-reactants including polyfunctional amines, acids (and acid anhydrides), phenols, alcohols and thiols (usually called mercaptans). These co-reactants are often referred to as hardeners or curatives, and the cross-linking reaction is commonly referred to as curing.

Reaction of polyepoxides with themselves or with polyfunctional hardeners forms a thermosetting polymer, often with favorable mechanical properties and high thermal and chemical resistance. Epoxy has a wide range of applications, including metal coatings, use in electronics/electrical components/LEDs, high tension electrical insulators, paint brush manufacturing, fiber-reinforced plastic materials and structural adhesives. Epoxy is sometimes used as a glue (see image at right).

Fiberglass

Fiberglass (US) or fibreglass (UK) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet (called a chopped strand mat), or woven into a fabric. The plastic matrix may be a thermoset polymer matrix—most often based on thermosetting polymers such as epoxy, polyester resin, or vinylester—or a thermoplastic.

Cheaper and more flexible than carbon fiber, it is stronger than many metals by weight, is non-magnetic, non-conductive, transparent to electromagnetic radiation, can be molded into complex shapes, and is chemically inert under many circumstances. Applications include aircraft, boats, automobiles, bath tubs and enclosures, swimming pools, hot tubs, septic tanks, water tanks, roofing, pipes, cladding, orthopedic casts, surfboards, and external door skins. Fiberglass covers are also widely used in the water-treatment industry to help control odors.Other common names for fiberglass are glass-reinforced plastic (GRP), glass-fiber reinforced plastic (GFRP) or GFK (from German: Glasfaserverstärkter Kunststoff). Because glass fiber itself is sometimes referred to as "fiberglass", the composite is also called "fiberglass reinforced plastic". This article will adopt the convention that "fiberglass" refers to the complete glass fiber reinforced composite material, rather than only to the glass fiber within it.

Frankincense

Frankincense (also known as olibanum, Hebrew: לבונה‎ [levona], Arabic: اللبان‎ al-libān or Arabic: البخور‎ al-bakhūr) is an aromatic resin used in incense and perfumes, obtained from trees of the genus Boswellia in the family Burseraceae, particularly Boswellia sacra (syn. B. bhaw-dajiana), B. carterii, B. frereana, B. serrata (B. thurifera, Indian frankincense), and B. papyrifera. The word is from Old French franc encens ("high-quality incense").There are five main species of Boswellia that produce true frankincense. Resin from each of the five is available in various grades, which depend on the time of harvesting. The resin is hand-sorted for quality.

Hashish

Hashish, or hash, is a drug made from the resin of the cannabis plant. It is consumed by smoking a small piece, typically in a pipe, bong, vaporizer or joint, or via oral ingestion (after decarboxylation). As pure hashish will not burn if rolled alone in a joint, it is typically mixed with herbal cannabis, tobacco or another type of herb for this method of consumption.

Depending on region or country, multiple synonyms and alternative names exist.Hash is an extracted cannabis product composed of compressed or purified preparations of stalked resin glands, called trichomes, from the plant. It is defined by the 1961 UN Single Convention on Narcotic Drugs (Schedule I and IV) as "the separated resin, whether crude or purified, obtained from the cannabis plant". The resin contains ingredients such as tetrahydrocannabinol (THC) and other cannabinoids—but often in higher concentrations than the unsifted or unprocessed cannabis flower. Purities of confiscated hashish in Europe (2011) range between 4-15%. Between 2000 and 2005 the percentage of hashish in cannabis end product seizures was at 18%.Hashish may be solid or resinous depending on both preparation and room temperature; pressed hashish is usually solid, whereas water-purified hashish—often called "bubble melt hash", or simply "bubble hash"—is often a paste-like substance with varying hardness and pliability; its color, most commonly light to dark brown, can vary from transparent to yellow, tan, black, or red. This all depends on the process and amount of leftover plant material (i.e. chlorophyl) Hashish was the primary form of cannabis used in Europe in 2008. Herbal cannabis is more widely used in Northern America.

High-density polyethylene

High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or "polythene" when used for HDPE pipes. With a high strength-to-density ratio, HDPE is used in the production of plastic bottles, corrosion-resistant piping, geomembranes and plastic lumber. HDPE is commonly recycled, and has the number "2" as its resin identification code.

In 2007, the global HDPE market reached a volume of more than 30 million tons.

Ion-exchange resin

An ion-exchange resin or ion-exchange polymer is a resin or polymer that acts as a medium for ion exchange. It is an insoluble matrix (or support structure) normally in the form of small (0.25–0.5 mm radius) microbeads, usually white or yellowish, fabricated from an organic polymer substrate. The beads are typically porous, providing a large surface area on and inside them. The trapping of ions occurs along with the accompanying release of other ions, and thus the process is called ion exchange. There are multiple types of ion-exchange resin. Most commercial resins are made of polystyrene sulfonate.

Ion-exchange resins are widely used in different separation, purification, and decontamination processes. The most common examples are water softening and water purification. In many cases ion-exchange resins were introduced in such processes as a more flexible alternative to the use of natural or artificial zeolites. Also, ion-exchange resins are highly effective in the biodiesel filtration process.

Mastic (plant resin)

Mastic (Greek: Μαστίχα) is a resin obtained from the mastic tree (Pistacia lentiscus). In pharmacies and nature shops, it is called Arabic gum (not to be confused with gum arabic) and Yemen gum. In Greece, it is known as tears of Chios, being traditionally produced on that Greek island, and, like other natural resins, is produced in "tears" or droplets.

Originally a sap, mastic is sun-dried into pieces of brittle, translucent resin. When chewed, the resin softens and becomes a bright white and opaque gum. The flavor is bitter at first, but after some chewing, it releases a refreshing flavor similar to pine and cedar.

Megachilidae

Megachilidae is a cosmopolitan family of mostly solitary bees whose pollen-carrying structure (called a scopa) is restricted to the ventral surface of the abdomen (rather than mostly or exclusively on the hind legs as in other bee families). Megachilid genera are most commonly known as mason bees and leafcutter bees, reflecting the materials from which they build their nest cells (soil or leaves, respectively); a few collect plant or animal hairs and fibers, and are called carder bees, while others use plant resins in nest construction and are correspondingly called resin bees. All species feed on nectar and pollen, but a few are kleptoparasites (informally called "cuckoo bees"), feeding on pollen collected by other megachilid bees. Parasitic species do not possess scopae. The motion of Megachilidae in the reproductive structures of flowers is energetic and swimming-like; this agitation releases large amounts of pollen.

Pitch (resin)

Pitch is a name for any of a number of viscoelastic polymers. Pitch can be natural or manufactured, derived from petroleum, coal tar, or plants. Various forms of pitch may also be called tar, bitumen, or asphalt. Pitch produced from plants is also known as resin. Some products made from plant resin are also known as rosin.

Poly(methyl methacrylate)

Poly(methyl methacrylate) (PMMA), also known as acrylic, acrylic glass, or plexiglass as well as by the trade names Crylux, Plexiglas, Acrylite, Lucite, and Perspex among several others (see below), is a transparent thermoplastic often used in sheet form as a lightweight or shatter-resistant alternative to glass. The same material can be used as a casting resin, in inks and coatings, and has many other uses.

Although not a type of familiar silica-based glass, the substance, like many thermoplastics, is often technically classified as a type of glass (in that it is a non-crystalline vitreous substance) hence its occasional historical designation as acrylic glass. Chemically, it is the synthetic polymer of methyl methacrylate. The material was developed in 1928 in several different laboratories by many chemists, such as William Chalmers, Otto Röhm, and Walter Bauer, and was first brought to market in 1933 by German Röhm & Haas AG (as of January 2019 part of Evonik Industries) and its partner and former U.S. affiliate Rohm and Haas Company under the trademark Plexiglas.PMMA is an economical alternative to polycarbonate (PC) when tensile strength, flexural strength, transparency, polishability, and UV tolerance are more important than impact strength, chemical resistance and heat resistance. Additionally, PMMA does not contain the potentially harmful bisphenol-A subunits found in polycarbonate. It is often preferred because of its moderate properties, easy handling and processing, and low cost. Non-modified PMMA behaves in a brittle manner when under load, especially under an impact force, and is more prone to scratching than conventional inorganic glass, but modified PMMA is sometimes able to achieve high scratch and impact resistance.

Resin extraction

Resin extraction consists of incising the outer layers of a pine tree in order to collect the sap or resin.

Resin identification code

The ASTM International Resin Identification Coding System, often abbreviated RIC, is a set of symbols appearing on plastic products that identify the plastic resin out of which the product is made. It was developed in 1988 by the Society of the Plastics Industry (now the Plastics Industry Association) in the United States, but since 2008 it has been administered by ASTM International, an international standards organization.

Retsina

Retsina (Greek: Ρετσίνα) is a Greek white (or rosé) resinated wine, which has been made for at least 2,000 years. Its unique flavor is said to have originated from the practice of sealing wine vessels, particularly amphorae, with Aleppo Pine resin in ancient times. Before the invention of impermeable glass bottles, oxygen caused many wines to spoil within the year. Pine resin helped keep air out, while infusing the wine with resin aroma. The Romans began to use barrels in the 3rd century AD, removing any oenological necessity for resin, but the flavor itself was so popular that the style is still widespread today.

Varnish

Varnish is a clear transparent hard protective finish or film. Varnish has little or no color and has no added pigment as opposed to paint or wood stain which contains pigment. However, some varnish products are marketed as a combined stain and varnish. Varnish is primarily used in wood finishing applications where the natural tones and grains in the wood are intended to be visible. It is applied over wood stains as a final step to achieve a film for gloss and protection. Varnish finishes are usually glossy but may be designed to produce satin or semi-gloss sheens by the addition of "flatting" agents.

The term "varnish" refers to the finished appearance of the product. It is not a term for any single or specific chemical composition or formula. There are many different compositions that achieve a varnish effect when applied. A distinction between spirit-drying (and generally removable) "lacquers" and chemical-cure "varnishes" (generally thermosets containing "drying" oils) is common, but varnish is a broad term historically and the distinction is not strict.

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