resin, any of a class of amorphous solids or semisolids. Resins are found in nature and are chiefly of vegetable origin. They are typically light yellow to dark brown in color; tasteless; odorless or faintly aromatic; translucent or transparent; brittle, fracturing like glass; and flammable, burning with a smoky flame. Resins are soluble in alcohol, ether, and many hydrocarbons but are insoluble in water. When heated, they soften and finally melt. Their chemical composition varies, but most are mixtures of organic acids and esters. Resins are generally classified according to their source or by such qualities as hardness or solubility. Natural resins are found as exudations, often as globules or tears, on the bark of various trees (mostly pines and firs) or on other living plants; they also occur as fossils or as exudations from the bodies of certain scale insects (see lac lac, resinous exudation from the bodies of females of a species of scale insect (Tachardia lacca), from which shellac is prepared. India is the chief source of shellac, although some is obtained from other areas in Southeast Asia.
..... Click the link for more information. ). Some natural resins, called oleoresins, contain both a resin and an essential oil; they are often viscid, sticky, gummy, or plastic. Other resins are exceedingly hard and resistant to most solvents, softening only at high temperatures. The primary uses for most resins are in varnish, shellac, and lacquer, in medicine, in molded articles (e.g., pipe mouthpieces), and in electrical insulators. See amber amber, fossilized tree resin . Amber can vary in color from yellow to red to green and blue. The best commercial amber is transparent, but some varieties are cloudy.
..... Click the link for more information. ; balsam balsam (bôl`səm), fragrant resin obtained from various trees.
..... Click the link for more information. ; benzoin benzoin (bĕn`zoin, –zōĭn) or benzoinum
..... Click the link for more information. ; Canada balsam Canada balsam, yellow, oily, resinous exudation obtained from the balsam fir . It is an oleoresin (see resin ) with a pleasant odor but a biting taste. It is a turpentine rather than a true balsam.
..... Click the link for more information. ; copaiba copaiba (kōpā`bə, –pī`–)
..... Click the link for more information. ; dragon's blood dragon's blood, name for a red resin obtained from a number of different plants. It was held by early Greeks, Romans, and Arabs to have medicinal properties; Dioscorides and other early writers described it.
..... Click the link for more information. ; mastic mastic, resin obtained from the small mastic tree Pistacia lentiscus (of the sumac family), found chiefly in Mediterranean countries. When the bark of the tree is injured, the resin exudes in drops. It is transparent and pale yellow to green in color.
..... Click the link for more information. ; rosin rosin or colophony, hard, brittle, translucent resin , obtained as a solid residue from crude turpentine . Usually pale yellow or amber, its color may vary from brownish-black to transparent depending on the nature of the source of the crude
..... Click the link for more information. ; turpentine turpentine, yellow to brown semifluid oleoresin exuded from the sapwood of pines, firs, and other conifers. It is made up of two principal components, an essential oil and a type of resin that is called rosin .
..... Click the link for more information. .

resin

Any natural or synthetic organic compound consisting of a noncrystalline (amorphous) solid or viscous liquid substance or mixture. Natural resins are usually transparent or translucent yellow to brown and can melt and burn. Most are exuded from trees, especially pines and firs (see conifer), when the bark is injured or stripped. The fluid secretion usually dries out and hardens into a material that can be worked. Natural resins have been used in perfumes and medicines (e.g., balsams), in paints and varnishes (e.g., turpentine and shellac, the latter derived from the secretion of an insect), and in decorative ware (e.g., amber, Oriental lacquer). Synthetic resins are all plastics; the term resin, though still used in the modern industry, dates from the years when synthetics began to replace natural resins. Thermoplastic resins are plastics such as polyethylene that can be shaped repeatedly on reheating, whereas thermosetting resins are plastics such as epoxy that set permanently and cannot be reshaped.

resin

1. any of a group of solid or semisolid amorphous compounds that are obtained directly from certain plants as exudations. They are used in medicine and in varnishes

2. any of a large number of synthetic, usually organic, materials that have a polymeric structure, esp such a substance in a raw state before it is moulded or treated with plasticizer, stabilizer, filler, etc

resin (redirected from resinous)

resin

resin
(redirected from resinous)