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Abietic acid
From Wikipedia, the free encyclopedia
| Abietic acid | |
|---|---|
 |
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| IUPAC name | (1R,4aR,4bR,10aR)-7-isopropyl- 1,4a-dimethyl-1,2,3,4,4a,4b,5,6,10,10a- decahydrophenanthrene-1-carboxylic acid |
| Other names | Abietic acid, Sylvic acid |
| Identifiers | |
| CAS number | |
| PubChem | |
| EINECS number | |
| RTECS number | TP8580000 |
| SMILES | O=C(O)C1(C2C(C3C(=CC2)C=C(CC3)C(C)C)(CCC1)C)C |
| InChI | InChI=1/C20H30O2/c1-13(2)14-6-8-16-15(12-14) 7-9-17-19(16,3)10-5-11-20(17,4)18(21) 22/h7,12-13,16-17H,5-6,8-11H2,1-4H3, (H,21,22)/t16-,17+,19+,20+/m0/s1 |
| Properties | |
| Molecular formula | C20H30O2 |
| Molar mass | 302.44 g/mol |
| Appearance | yellow resinous powder, crystals or chunks |
| Melting point |
139 - 142 °C |
| Boiling point |
250 °C at 9 mmHg |
| Solubility in water | Insoluble |
| Hazards | |
| MSDS | MSDS |
| Main hazards | Irritant |
| R-phrases | R36/37/38 |
| S-phrases | S26 S36 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Abietic acid (also known as abietinic acid or sylvic acid), a resin acid, is the primary irritant in pine wood and resin, isolated from rosin (via isomerization) and is the most abundant of several closely related organic acids that constitute most of rosin, the solid portion of the oleoresin of coniferous trees. Its ester is called an abietate.
Abietic acid is a weak contact allergen, however compounds resulting of its oxidation by air elicit stronger response. It is soluble in alcohols, acetone, and ethers.
Commercial abietic acid is usually a glassy or partly crystalline, yellowish solid that melts at temperatures as low as 85° C (185° F). It belongs to the diterpene group of organic compounds (compounds derived from four isoprene units). It is used in lacquers, varnishes, and soaps, and for the analysis of resins and the preparation of metal resinates. It is listed in the Toxic Substances Control Act inventory.
Rosin has been used for centuries for caulking ships. It is also rubbed on the bows of musical instruments to make them less slippery. In modern times methods have been developed for improving the properties of the rosin acids, which are soft, tacky, and low-melting and subject to rapid deterioration by oxidation in air. Stability is greatly increased by heat treatment.
Rosin acids are converted into ester gum by reaction with controlled amounts of glycerol or other polyhydric alcohols. Ester gum has drying properties and is used in paints, varnishes, and lacquers.