Resin acid

Source: Wikipedia, the free encyclopedia.

Resin acid refers to mixtures of several related

2-ethylhexanoic acid or petroleum-derived naphthenic acids
.

Botanical analysis

Resin acids are

temperate coniferous forests. The resin acids are formed when two-carbon and three-carbon molecules couple with isoprene building units to form monoterpenes (volatile), sesquiterpenes (volatile), and diterpenes
(nonvolatile) structures.

sapwood
, however, is less at the base of the tree and increases with height.

In 2005, as an infestation of the

blue stain fungus devastated the Lodgepole Pine forests of northern interior British Columbia
, Canada, resin acid levels three to four times greater than normal were detected in infected trees, prior to death. These increased levels show that a tree uses the resins as a defense. Resins are both toxic to the beetle and the fungus and also can entomb the beetle in diterpene remains from secretions. Increasing resin production has been proposed as a way to slow the spread of the beetle in the "Red Zone" or the wildlife urban interface.

Chemical components

Abietic-type acids

The terpenoid abietic acid is a common resin acid.
  • Represents the majority 85-90% of typical tall oil.
  • abietic acid
    • abieta-7,13-dien-18-oic acid
    • 13-isopropylpodocarpa -7,13-dien-15-oic acid
  • Neoabietic acid
  • Dehydroabietic acid
  • Palustric acid
  • Levopimaric acid
  • Simplified formula C20H30O2, or C19H29COOH
  • molecular weight
    302

Pimaric-type acids

The terpenoid pimaric acid is a common resin acid.

Production in tall oil (chemical pulping byproduct)

See also: Tall oil

The commercial manufacture of

kraft soap, or resin soap.[1]

Kraft soap can be reneutralized with

unsaponifiable sterols
.

Resin acids, because of the same protectant nature they provide in the trees where they originate, also impose toxic implications on the effluent treatment facilities in pulp manufacturing plants. Furthermore, any residual resin acids that pass the treatment facilities add toxicity to the stream discharged to the receiving waters.

Variation with species and biogeoclimatic zone

The chemical composition of tall oil varies with the species of trees used in pulping, and in turn with geographical location. For example, the coastal areas of the southeastern United States have a high proportion of

Loblolly Pine
(Pinus taeda). Slash Pine generally contains a higher concentration of resin acids than Loblolly Pine.

In general, the tall oil produced in coastal areas of the southeastern United States contains over 40% resin acids and sometimes as much as 50% or more. The

Shortleaf Pine
(Pinus echinata) are more dominant, the resin acid content decreases to as low as 30-35% with a corresponding increase in the fatty acids present.

In

Scots Pine
(Pinus sylvestris) may vary from 20 to 50%, fatty acids from 35 to 70%, and unsaponifiables from 6 to 30%.

References

  1. doi:10.1002/14356007.a26_057
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