Aliphatic acid esters of wood

Table IV. Apparent Melting Temperature of Various Higher Aliphatic Acid Esters of Wood Prepared by the TFAA or the Chloride Method...

When wood is reacted with aliphatic acids, acid anhydrides, or acid chlorides, aliphatic acid esters of wood are obtained as follows [Reactions (10)-(12)] ... 

Further detailed thermal and other properties of the above aliphatic acid esters of wood have been described in the reviews by Shiraishi et al. [3-7]. 

Acetylene, polymerization, 433-34 Acrylic polymers, 105 Aliphatic acid esters of wood,... 

Synonyms Abietic acid methyl ester Methyl [1 R-( 1 a,4ap,4ba, 10aa)]-1,2,3,4,41,4b,5,6,10,10a-decahydro-1,4a-dimethyl-7-(1-methylethyl)-1-phenanthrenecarboxylate Methyl ester of wood rosin 1-Phenanthrenecarboxylic acid, 1,2,3,4,4a,4b,5,6,10,10a-decahydro-1,4a-dimethyl-7-(1-methylethyl)-, methyl ester, [1R-(1 a,4ap,4ba, 10aa)]- Podocarpa-7,13-dien-15-oic acid, 13-isopropyl-, methyl ester Wood rosin, methyl ester Definition Commercial prod, is a mixt. of methyl esters of the rosin acids Empirical C21H32O2 Formula C19H29COOCH3 Properties Colorless to yel. thick liq., odorless misc. with alcohol, ether, common org. soivs., aliphatic hydrocarbons insol. in water m.w. 316.47 dens. 1.03 b.p. 360-365 C (dec.) flash pt. (COC) 180 C ref. index 1.53 (20 C)... 

Nakano and Nakamura [65-69] studied viscoelasticity of wood specimens prepared with TFAA and aliphatic acids such as propionic, n-valeric, n-caproric, /i-capric, lauric, and palmitic acids. It was found that, with increase in the ester content, the relaxation rigidity decreases markedly and its temperature dependence becomes high [65]. The real part of complex rigidity decreases rapidly with increasing number of C atoms of the introduced acyl group [68]. The rate of decrease increases with increasing temperature. Further, the... 

Sulfolane, another highly polar solvent, is used to separate aromatic hydrocarbons from aliphatic hydrocarbons [10]. The extraction process first developed by Shell Oil in 1959 and which is referred to as the Sulfolane process is used worldwide. The solvency of sulfolane for certain fatty acids and fatty acid esters is the basis for upgrading animal and vegetable fatty acids used in food products, paints, plastics, resins, and soaps. Aqueous solutions containing 30-70 wt% sulfolane are used to remove lignin from wood chips [11]. Sulfolane is used to remove acidic components like hydrogen sulfide and carbon dioxide from gas feed stocks. 

In the field of biological materials the fats (solids) and oils (liquids), which are esters of glycerol and aliphatic acids of high molecular weight, have special importance. "Fatty acids" are organic acids that occur in fats and oils (as esters.) Saturated fatty acids are linear and tend to pack like sticks of wood, to form solid masses in blood vessels. The trans unsaturated fatty acids have a slight Z-shape kink in the chain, but are also linear. By contrast, cis imsaturated fatty acids are bent, so do not pack as well as linear structures and do not collect in blood vessels. Many natural vegetable fats contain esters of cis unsaturated fatty acids. 

These and other bond cleavage reactions that proceed through ionic mechanisms explain the release of CO2, CO and CH4. The low temperature evolution of CO2 and CO is consistent with the observed reduction in C==0 functionality found, in part, by esters and carboxylic acid groups in the parent wood (mostly present in hemicellulose and lignin). The substantial release of CH4 at similar temperatures suggests that the cleavage of aliphatic side chains is relatively facile, and is consistent with a loss of aliphatic character and a corresponding increase in aromaticity. 

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