RESINS AND TURPENTINE


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CHAPTER 10 IN THE TEXT, p. 257

Introduction
Resins have played an important role in many cultures. They are part of paints, incense, and ship caulking. Some have been replaced by synthetic materials, whereas others have not been. In the plant, resins are actively synthesized and secreted into specialized canals or ducts. They probably are involved in wound responses or in limiting herbivory to the plants.
In contrast to gums, resins are insoluble in water. Most gum plants came from the Old World; the same thing is true for resin plants, although some important ones came from the New World as well.
One of the most ancient uses of resins was as part of incense. Most resins are hydrocarbon-like and burn. Two classical resins used for this purpose were frankincense (Boswellia carteri, Burseraceae) and myrrh (Commiphora myrrha, Burseraceae).
The value of these resins in the time of Christ is illustrated by the fact that the wise men brought them as gifts along with gold. Both plants are native to East Africa (Ethiopia). They were early products of trade. They are removed as drops from the trees. Neither is especially valuable today.
Many of these resins were also used for embalming by the Egyptians.
Other important resins are mastic and lacquer (not to be confused with liquor) [(or shellac)]. Mastic comes from Pistachia lentiscus, Anacardiaceae. Lacquer (one kind) somes from Rhus verniciflua, Anacardiaceae. Both are used for sealing articles, especially wood carvings etc. The Chinese and Japanese made an art form out of it.
Many people are highly sensitive to the Japanese and Chinese ones as that type of lacquer contains compounds similar to those in poison ivy.

Copal (from Copaiferaor Hymenaeaspecies and from Agathis, Araucariaceae) are used to coat art work etc. The resin from Copaiferais sometimes called copaiba balsam. Dammars from members of the family Dipterocarpaceae (especially Shoreaspecies) are used in similar manners.

Copal

Other natural resins are used in adhesives, soaps, sizing, floor coatings, pharmaceuticals, fireworks, incense, leather finishes, and lithography. They are used in varnishes, but have largely been replaced by better quality synthetic materials.

Balsam-of-Peru
This resin comes from a tree, Myroxylon balsamum, Fabaceae or Leguminosae that grows mostly in Central America. Most of the supply comes from El Salvador. The resin is used for medicinal purposes as an antiseptic, as a fixative for perfumes and in soaps.
In the old days, it was shipped through the port of Callao in Peru. The tree is about 100 feet tall. The collectors cut out a small panel from the tree and stuff it full of rags. Then, they burn and bruise the tree above the cut open area. Later, they collect these rags and remove the resin.

Balsam of peru

Gum elemi
This is a resin from Bursera and Protium species and from Canarium luzonicum.

Kauri resin
This resin comes from Agathis australis (kauri) in New Zealand (Araucariaceae).

Turpentine and rosin
Turpentine is tapped from a number of trees. In the U.S., the most important one was Pinus palustris, the long leaf pine. The material obtained is then distilled to remove the volatile essential oils that are called "spirits of turpentine".
These are still used as a solvent, but have largely been replaced by petroleum derived hydrocarbons.
Tapping now often involves application of plant hormones, sulfuric acid or paraquat to improve yields. The wood is used after the trees have been tapped extensively, but is not of as good quality.
Much turpentine is derived from tall oil from the paper industry. The distillation is now carefully controlled and done in more sophicated plants.
The remaining material (made up largely of diterpene acids) is called rosin. Rosin is used for violinist bows, for boxing gloves, and baseball pitchers. Rosin is also used in printer's inks, paper coatings, soaps, varnishes, sealants, tin can linings, plywood manufacture etc.
Rosin used to be used to make linoleum. This material has almost completely been replaced by vinyl flooring. A number of adhesives contain rosin. Other similar ones are purely synthetic.
The crude material sticks to everything, including the worker's heels and they used to be called "tar-heels". The name stuck in North Carolina.

Naval stores
Resins from gymnospermous trees (especially Pinusspecies) have been used for millenia to caulk ships. This was done in Europe and later in the U.S. These materials were also used to waterproof containers of various types in the Old World, but also by the American Indians.

Amber
Amber is fossilized rosin. The source in the temperate areas of the world tends to be gymnosperms whereas that in the tropics tends to be legumes. Amber is widely used for jewelry.

Lac
Lac used to make shellac is actually an insect product. The insects live on several trees of the Fabaceae (Butea, Cajanus, Acacia), Rhamnaceae (Zizyphus), Sapindaceae (Schleicheria). The insect (Laccifer lacca) is a scale insect. The reddish translucent material from the insect (called "seed lac") is treated with minerals and other resins to make "shellac". Shellac is used in high polish interior spirit varnishes and waxes. Most of it comes from India.


Rubber, Gutta, and Chicle

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Revised March 2005
© David S. Seigler, Integrative Biology 2005, Plants and Their Uses, Department of Plant Biology, 265 Morrill Hall, 505 S. Goodwin Ave., University of Illinois, Urbana, Illinois 61801, USA. 217-333-7577. seigler@life.uiuc.edu.