Resin - a chemical

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Offline jsrsol

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Resin - a chemical
« on: 24/06/2009 10:15:53 »
Resin is a hydrocarbon secretion of many plants, particularly coniferous trees. It is valued for its chemical constituents and uses, such as varnishes and adhesives, as an important source of raw materials for organic synthesis, or for incense and perfume. Fossilized resins are the source of amber. Resins are also a material in nail polish.

The term is also used for synthetic substances of similar properties. Resins have a very long history and are mentioned by both ancient Greek Theophrastus and ancient Roman Pliny the Elder, especially as the forms known as frankincense and myrrh. They were highly prized substances used for many purposes, especially perfumery and as incense in religious rites.

The resin] produced by most plants is a viscous liquid, composed mainly of volatile fluid terpenes, with lesser components of dissolved non-volatile solids which make resin thick and sticky. The most common terpenes in resin are the bicyclic terpenes 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. The individual components of resin can be separated by fractional distillation

A few plants produce resins with different compositions, most notably Jeffrey Pine and Gray Pine, the volatile components of which are largely pure n-heptane with little or no terpenes. The exceptional purity of the n-heptane distilled from Jeffrey Pine resin, unmixed with other isomers of heptane, led to its being used as the defining zero point on the octane rating scale of petrol quality. Because heptane is highly flammable, distillation of resins containing it is very dangerous. Some resin distilleries in California exploded because they mistook Jeffrey Pine for the similar but terpene-producing Ponderosa Pine. At the time the two pines were considered to be the same species of pine; they were only classified as separate species in 1853.

Some resins when soft are known as 'oleo-resins', and when containing benzoic acid or cinnamic acid they are called balsams. Other resinous products in their natural condition are a mix with gum or mucilaginous substances and known as gum resins. Many compound resins have distinct and characteristic odors, from their admixture with essential oils.

Certain resins are obtained in a fossilized condition, amber being the most notable instance of this class; African copal and the kauri gum of New Zealand are also procured in a semi-fossil condition.
« Last Edit: 24/06/2009 20:07:43 by JimBob »

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Offline Bored chemist

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Re: Resin - a chemical
« Reply #1 on: 24/06/2009 19:43:45 »
Snap!
http://en.wikipedia.org/wiki/Resin
Except that your post has a crappy spam link in it.
I think that's two breaches of the site policy in your first post.
Please disregard all previous signatures.

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Offline JimBob

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Resin - a chemical
« Reply #2 on: 24/06/2009 20:09:57 »
Not anymore it doesn't - Oh, and if you wish to become un-banned, jsrsol, you need to do some fancy tap dancing.
The mind is like a parachute. It works best when open.  -- A. Einstein

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Offline Make it Lady

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Resin - a chemical
« Reply #3 on: 24/06/2009 20:17:37 »
Oh, I like resin. I thought it was going to be a really good thread GRRRRRR!
Give a man a fire and he is warm for a day, set a man on fire and he is warm for the rest of his life.

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Offline Don_1

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Resin - a chemical
« Reply #4 on: 25/06/2009 14:56:51 »
My first job was chemical analysis of in-production resins, melamine and soy sauce.

How did I get from there, to exhibitions???
If brains were made of dynamite, I wouldn't have enough to blow my nose.

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Offline Make it Lady

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Resin - a chemical
« Reply #5 on: 25/06/2009 20:04:49 »
My first job was analysing resin coated sand for engine mountings. Dull job but I loved making little moulded sand shapes. It was like permanent beach sculptures.
Give a man a fire and he is warm for a day, set a man on fire and he is warm for the rest of his life.