Pine terpene

(materials) Any terpene in the essential oils obtained from various Pinus species.

A major component of the essential oils obtained from various Pinus species. The principal terpenes of the oil of southern pines [longleaf pine (P. palustris) and slash pine (P. caribaea)] are α- and β-pinene, whose structures are shown below.

Gum turpentine (gum spirits) is the volatile fraction of the oleoresin that exudes from cuts made in the trunks of live trees. The resin is collected and distilled by a process that yields about 20% turpentine, mainly α- and β-pinene, and 70% rosin; it was the basis of the original naval stores industry.

Wood turpentine is obtained by steam distillation from stumps and other logging residues. The volatile material in this case consists of about 50% turpentine and 30–40% of higher-boiling-point alcohols; the latter fraction is known as pine oil. The bulk of the wood turpentine and pine oil produced by modern industrial processes is a by-product of the sulfate wood-pulping process (sulfate turpentine).

Important uses of turpentine or the purified pinenes derived from turpentine are in terpene resins, as a thinner in paints and varnishes, and as a starting material in the synthesis of other commercially valuable terpenes.

Pine oil is a mixture of monoterpene alcohols, mainly α-terpineeol, obtained in large amounts mixed with wood turpentine or sulfate turpentine. The term pine oil is also used to designate the essential oil of various species of pine.

Much of the pine oil of commerce is prepared synthetically by acid-catalyzed hydration of α-pinene. This process involves a complex series of reaction that occur via cationic intermediates.

The composition of industrial-grade pine oil is approximately 65% α-terpineol, 20–25% of other monoterpene alcohols, and 10–15% hydrocarbons. Pine oil has surfactant and emulsifying properties and is also a disinfectant. Most of the pine oil manufactured is used in the manufacture of cleanser and textile penetrants. See also Surfactant; Wood chemicals.