Coniferous resins

Terpenoids are susceptible to a number of alterations mediated by oxidation and reduction reactions. For example, the most abundant molecule in aged Pinus samples is dehydroabietic acid [Structure 7.10], a monoaromatic diterpenoid based on the abietane skeleton which occurs in fresh (bleed) resins only as a minor component. This molecule forms during the oxidative dehydrogenation of abietic acid, which predominates in rosins. Further atmospheric oxidation (autoxidation) leads to 7-oxodehydroabietic acid [Structure 7.11]. This molecule has been identified in many aged coniferous resins such as those used to line transport vessels in the Roman period (Heron and Pollard, 1988 Beck et al., 1989), in thinly spread resins used in paint media (Mills and White, 1994 172-174) and as a component of resin recovered from Egyptian mummy wrappings (Proefke and Rinehart, 1992). 

Apart from the n-alkanes discussed above, epicuticular wax hydrocarbons contain sesqui- and diterpenoids. These compounds are based on the structural skeletons of cadinane and abietane, respectively, which are shown in Fig. 7-24. The sesquiterpenoids recovered by Simoneit and Mazurek (1982) in the rural aerosol were calamenene, tetrahydrocadalane, and cadalene. These compounds presumably are degradation products of cadinane derivatives (various isomers of cadinenes and cadinols), which are ubiquitous in essential oils of many higher plants (Simonsen and Barton, 1961). The major diterpenoid hydrocarbons observed in the aerosol samples were dehy-droabietane, dehydroabietin, and retene. The main source of abietane derivatives are coniferous resins. The parent compounds dehydrate fairly rapidly to yield the more stable hydrocarbons found in the aerosols. These may then serve as markers for hydrocarbons arising from vegetation, in addition to the odd-to-even carbon number preference in the n-alkanes. 

Apart from saturated fatty acids, Simoneit and Mazurek (1982) observed low concentrations of unsaturated fatty acids (range C,4-Ci7) a-hydroxy fatty acids (range C 0-C24) that are known components of grass wax dicarboxylic acids (range C 0-C24) that probably arise from the direct biodegradation of hydroxy fatty acids and diterpenoidal acids occurring as diagenetic products of diterpenoids from coniferous resins. 

Solvent-Soluble Natural Polymers. The exudate of the lac insect is dissolved in alcohol to yield shellac. This solution has adhesive properties and should be reversible by treatment with the appropriate alcohol or similar solvent, although it may present problems in other performance areas (8). Solvent-soluble plant gums, especially coniferous resins (e.g., from firs or pines) can be dissolved in organic solvents and used as adhesives. Solvent solutions of some plant waxes may also have limited utility in gluing. All such glues should be reversible by treatment with solvents similar to those they were dissolved in when applied. 

The solvent-based candidates include various solvent-soluble natural and synthetic polymers (e.g., shellac, coniferous resins, cellulose nitrate, acrylics, contact-bond glues). 

Fats, oils, beeswax, bitumen, coniferous resin, mastic resin [54,56]... 

Tall oil rosin is obtained from crude tall oil obtained from the Kraft (sulphate) pulping of various coniferous trees in the paper manufacturing industry. During the Kraft pulping process the fatty acids and the resin acids from the coniferous wood are saponified by the alkaline medium. On concentration of the resulting pulping liquor, the sodium soap of these mixed acids rises to the surface from where they are skimmed out. By acidification of this material with sulphuric acid, the crude tall oil is obtained. Fractional steam distillation of the crude tall oil allows the separation of the tall oil fatty acids and the tall oil rosins [21]. 

Rosin is an organic flux that has long been used for soldering. It is a yellow, transparent, and relatively hard resin secreted from wounds in the trunks of coniferous trees. Rosin is insoluble in water, and its exact composition and structure are as yet unknown. 

Mono-, sesqui-, and some diterpenoids are found in marine and terrestrial flora. They are, therefore, not always unambiguous tracers for higher plant sources. However, diterpenoids with the abietane and pimarane (Fig. 1), and less common phyllocladane and kaurane, skeletons are predominant constituents in resins and supportive tissue of coniferous vegetation (Coniferae), which evolved in the late Paleozoic (200—300 million years ago). Diterpenoid biomarkers have been characterized in... 

Physical Form. Volatile liquid, colorless or yellow, which is a mixture of natural substances obtained ftom resinous exudates or resinous wood ftom living or dead coniferous trees, especially pine trees. The chemical composition can vary with the source and method of derivation, but a typical analysis of turpentine is a-pinene, 82.5% camphene, 8.7% (3-pinene, 2.1% unidentified natural turpenes, 6.8%. 

Retene is a methyl isopropyl phenanthrene (Fig. 2). As mentioned above, Wakeham [43] was the first to address the natural non-combustion production of retene in relation to lake sediments. The starting material for retene is abietic acid, a diterpenoid found primarily in the resin of coniferous trees. When burned, the abietic acid forms retene. It can also degrade via one of two pathways to retene without combustion (Fig. 5). One pathway is through dehydro abietin and another intermediate to retene. The other proceeds through dehydroabietane, another intermediate to simonellite and finally to retene. These mechanisms can occur in both the atmosphere [44] and in aquatic systems. Therefore, where there is abietic acid, retene can follow. This becomes especially important in areas where there are high densities of conifers, and thus abietic acid. 

Nahum LS (1969) Estimation of double bond content in lignin from the results of the oxo reaction of wood and lignin model compounds Tappi 52 712-714 Pew JC, Connors WJ (1971) Color of coniferous lignin Tappi 54 245-251 Redinger L (1961) Alkali lignin, its condensation products with phenols, and preparation of curable resins Monatsber Dtsch Akad Wiss (Berl) 3 571-578 Richtzenhain H, van Hofe C (1939) A stilbene derivative from the sulfite waste liquor Chem Ber 72 1890-1892... 

Chemical pulp starts with logs that have had their bark peeled off and that have been reduced to chips. The wood chips are boiled in strong caustic solutions that dissolve away parts of the wood that are not cellulose, such as lignin and resin, and leave the cellulose fibers more or less free. There are two chief processes for producing chemical pulp the kraft process, and the sulfite process. The kraft process uses the wood of either deciduous (e.g., poplar) or coniferous trees (e.g., spruce, fir, and hemlock) and produces a very strong paper. The sul-... 

Fossil resin of extinct coniferous tree (Succinite) extinct. J Perfume—4th lunar mansion medicinal amulet (worn by Roman women as protection from witches). 

Both the terms resin and plastic are in common use but there are no explicit definitions for them. The term resin originally referred to vegetable-derived organic products of relatively high molecular weight, the best known of which are rosin and balsam obtained from coniferous trees. But, the term is now used much more broadly, and rather loosely, to include the manmade polymeric substances used in a variety of applications, such as in plastics, textiles, and paints. It is often used interchangeably with the term plastic . 

When the beeswax has completely melted, remove it from the heat and slowly add 14 cup of turpentine. Mix thoroughly. Turpentine, made from the resin of coniferous trees, is an environmentally-friendly solvent. 

European Spruce. Spruce is a coniferous wood composed of only tracheids (thin-walled in the springwood and thick-walled in the latewood), parenchyma cells in the rays, and thick-walled epithelium cells around resin... 

Amber (succinite). General term for fossilized terpenoid resins from the Tertiary period formed from resinous secretions of coniferous trees. They owe their hardness and poor solubility to the evaporation of volatile terpenes as well as to autoxidation and polymerization of resin acids and alcohols. The resin alcohols are mostly esterified with succinic acid. - [HS253090]... 

CI oH I gO, Mr 154.25. A bicyclic monoterpene with the fenchane structure that was first detected in the turpentine oil of the pine Pinus palusiris. Various stereoisomers and their mixtures occur in numerous plant oils, e.g., (-)-j8-F. (oil, [a]o° -31°), in the essential oil of Lawson s cypress (Chamaecyparis lawsoniana, Cupressaceae) or (+)-a-F. (cryst., mp. 47-47.5 °C, [a] +12.5°) from the marsh resin obtained from peat bogs (= kauri resin of the tree Agathis australis, Araucaria-ceae). Fenchyl acetate is used in perfumes with a coniferous nuance. 

In contrast to the sulfite process, coniferous woods, sawdust, and high resin woods can be used in the sulfate process. The wood is boiled for some hours with a solution of sodium hydroxide, sodium carbonate, and sodium sulfide at 165-175° C. It is presumed that some of the cellulose hydroxyl groups are converted to sulfhydryl groups at this stage. The mercaptan groups formed are not stable in alkali and attack the ether cross-links of lignin by... 

Resins are most often considered to be hydrocarbons secreted from many plants, especially coniferous trees. See Fig. 1 [2]. They are viscous liquids containing volatile fluid terpenes and some dissolved nonvolatile solids that make them thick... 

Pinenes are the most interesting because they can be easily isolated by steam-distiUation from the resins of coniferous trees. 

Coniferous woods, sawdust, and high-resin woods can also be treated with the sulfate procedure. Sulfate pulp is more opaque and voluminous than sulfite pulp. Terpentine-like liquid resins ( pine oils ) are recovered as by-products from the exhaust gases. 

Resin is used to refer to hydrocarbon secretions of many plants, particularly coniferous trees. The resins are complex lipid-soluble mixtures of both non-volatile and volatile compounds. The non-volatile fraction consists of diterpenoid and triterpenoid compounds, while the volatile fraction is mostly composed of mono- and sesquiterpenoids. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food-glazing agents. ... 

Lignin lig-n9n (1822) n. The major noncarbohydrate constituent of wood and woody plants, functioning in nature as a binder to hold the matrix of cellulose fibers together. Lignins are obtained commercially from by-products of coniferous woods, for example, by treating wood flour with a derivative of lignosulfonic acid. They are used as extenders in phenolic resins, and sometimes as reactants in the production of phenol-formaldehyde resins. Hoadley RB (2000) Understanding wood. The Taunton Press, Newtown, CT. 

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