Cashew nut

Most nuts for commercial use are characteri2ed by high oil and protein contents (see Proteins) as well as a low percentage of carbohydrates (qv). However, some varieties, mostly inedible tree nuts such as acorn, horse chestnut, and chufa, contain at least as much sugar and/or starch as protein. The edible water chestnut is also in this category, as is the cashew nut, which contains starch in addition to a rich store of oil. The proximate composition of a number of nuts and of some nut products are given in Table 2 (3). 

Fig. 2. Toxic compounds found in cashew nuts (8 and 9) and in walnuts and walnut trees (10 and 11). See text.

Other higher boiling phenolic bodies obtainable from coal tar distillates are sometimes used in the manufacture of oil-soluble resins. Mention may also be made of cashew nut shell liquid which contains phenolic bodies and which is used in certain specialised applications. 

During the past four decades phenolic resins have become of increased significance in rubber compounding. For example, the resin based on cashew nut shell liquid, which contains phenolic bodies such as anacardic acid (Figure 23.23), may, when blended with hexamine, be incorporated into nitrile rubber (butadiene-acrylonitrile rubber). 

Corundum (AljOj) Vegetable oil mists (except castor cashew nut, or similar irritant oils) Sucrose, Tin Oxide, Titanium Dioxide Silicoh Carbide... 

Structural carbon shapes fabricated by heating coke with a mixture of tar and pitches are porous and are made impermeable by impregnation with a resin (usually a phenolic resin). Cashew nut shell liquid resin is used when resistance to alkalis and acids is required. 

Resol resins thermoset on heating and are used for adhesives. Novolacs require a further source of formaldehyde in the form of hexamethylenetetramine to produce molding powders. Phenolic moldings are resistant to heat, chemicals, and moisture with good electrical and heat insulation qualities. Complex phenols from, e.g., cashew-nut shell liquid, are used in making brake... 

Akajou, m. acajou (either cashew or mahogany tree), -harz, n. acajou resin, -nuss, /. cashew nut, -31, n. cashew (nut) oil. Akaridentod, m. acaricide. 

Anacardium occidentalle L. Cashew nut shell Anacardic acid, Cardanol, Brazil, Tanzania, Kenya, Nigeria... 

This is one of the most widely distributed plants cultivated formally to obtain the well-known edible nut popularly known as a cashew nut. The phenolic lipid is only... 

Figure 8 Cross-section of cashew nut showing the Honeycomb structure [133J.

Indian Cashew Nut Shell Liquid—A Versatile Industrial Raw Material of Great Promise—Regional Research Laboratory, Trivandrum and Cashew Export Promotion Council, Ernakulam (1983). 

Development of Value Added Polymer Resins Products from Cashew Nut Shell Liquid, Project report No. RT.09/MO/50, Regional Research Laboratory, Trivandrum (1987). 

Substituted phenols such as cresols, p-fcrf-butylphenol, / -phcnylphenol, resorcinol, and cardanol (derived from cashew nut shells) have also been used as precursors for phenolic resins. Alkylphenols with at least three carbons in the substituent lead to more hydrophobic phenolic resins that are compatible with many oils, natural resins, and rubbers.7 Such alkylphenolic resins are used as modifying and crosslinking agents for oil varnishes, as coatings and printing inks, and as antioxidants and stabilizers. Bisphenol-A (2,2-p-hydroxyphenylpropane),... 

Cardanol, a main component obtained by thermal treatment of cashew nut shell liquid (CNSL), is a phenol derivative having mainly the meta substituent of a C15 unsaturated hydrocarbon chain with one to three double bonds as the major. Since CNSL is nearly one-third of the total nut weight, a great amount of CNSL is obtained as byproducts from mechanical processes for the edible use of the cashew kernel. Only a small part of cardanol obtained in the production of cashew kernel is used in industrial fields, though it has various potential industrial utilizations such as resins, friction-lining materials, and surface coatings. Therefore, development of new applications for cardanol is very attractive. 

The processing of cashew nuts produces an enormous amount of cashew nut shells, which is a potential industrial waste that upon thermal treatment yields a dark-brown... 

Figure 10.2 Major components of cashew nut shell liquid.

Talbiersky, J., Polaczek, J., Ramamoorty, R. and Shishlov, O. (2000) Phenols from cashew nut shell oil as a feedstock for making resins and chemicals. OIL GAS European Magazine, 35, 33-40. 

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