Everything about Oleoresin totally explained
Resin, not to be confused with
rosin, 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.
The term is also used for synthetic substances of similar properties. Resins have a very long history and are mentioned by both
Theophrastus and
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 religuous rites.
Chemistry
The resin produced by most plants is a
viscous liquid, typically 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's 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're 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.
Derivatives
Solidified resin from which the volatile terpene components 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 odour and taste.
It is insoluble in water, mostly soluble in alcohol, essential oils, ether and hot fatty oils, and softens and melts under the influence of heat, isn't capable of
sublimation, and burns with a bright but smoky flame.
This comprises a complex mixture of different substances including organic acids named the
resin acids. These are closely related to the terpenes, and derive from them through partial
oxidation. Resin acids can be dissolved in
alkalis to form
resin soaps, from which the purified resin acids are regenerated by treatment with acids. Examples of resin acids are
abietic acid (sylvic acid), C
20H
30O
2,
plicatic acid contained in cedar, and
pimaric acid, C
20H
35O
2, a constituent of
gallipot resin. Abietic acid can also be extracted from rosin by means of hot alcohol; it crystallizes in leaflets, and on oxidation yields
trimellitic acid,
isophthalic acid and
terebic acid. Pimaric acid closely resembles abietic acid into which it passes when distilled in a
vacuum; it has been supposed to consist of three isomers.
Synthetic resins
Synthetic resins are materials with similar properties to natural resins—
viscous liquids capable of hardening. They are typically manufactured by
esterification or
soaping of
organic compounds.
The classic variety is
epoxy resin, manufactured through
polymerization-polyaddition or polycondensation reactions, used as a
thermoset polymer for adhesives and
composites. One more category, which constitutes 75% of resins used, is unsaturated polyester resin.
Ion exchange resin is another important class with application in
water purification and
catalysis of
organic reactions. See also
AT-10 Resin,
melamine resin. Another synthetic polymer is also sometimes called by the same suffix,
acetal resin. By contrast with the other synthetics, however, it has a simple chain structure with the
repeat unit of form -[CH
2O]-.
Uses
The hard transparent resins, such as the
copals,
dammars,
mastic and
sandarac, are principally used for
varnishes and
cement, while the softer odoriferous oleo-resins (
frankincense,
elemi,
turpentine,
copaiba) and gum resins containing essential oils (
ammoniacum,
asafoetida,
gamboge,
myrrh, and
scammony) are more largely used for therapeutic purposes and
incense.
Resin in the form of
rosin is used for the upkeep of bows for stringed instruments (for example
violin,
viola,
cello,
double bass), because of its quality for adding friction to the hair. Ballet dancers may apply crushed rosin to their shoes to increase grip on a slippery floor.
Resin has also been used as a medium for sculpture by artists such as
Eva Hesse, and in other types of artwork.
Also, resin is used in some
skateboard decks. It makes the skateboard more durable, making it less likely to get pressure cracks, chippings, or break in half.
In
Pompeii, resin is now used instead of
plaster to recreate the bodies of
Mount Vesuvius' victims, because it's more durable.
Akira Ifukube, who wrote and composed the music to numerous
Godzilla films, also created
Godzilla's roar by rubbing a resin-covered leather glove over the loosened strings of a
double bass.
Further Information
Get more info on 'Oleoresin'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://resin.totallyexplained.com">Resin Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |