The phenolic properties of CNSL are utilized to make condensation polymers by reaction with formaldehyde, furfural, etc. CNSL-based polymers are compatible with a wide variety of polymers such as alkyds, melamines, polyesters, etc.ĬNSL undergoes all the conventional chemical reactions of phenols. The polymers show flexibility due to internal plasticization resulting from the presence of a long side chain, which also offers water resistance. Polymers made from CNSL have certain outstanding properties which make them unique for many applications. These salts are generally used to the extent of 1 to 6%. CNSL can also be polymerized using salts such as zinc chloride, stannic chloride, ferrous sulphate, aluminium sulphate, boron trifluoride, and salts of iron, cobalt, nickel, boron, chromium, lead, silver, mercury, manganese, etc. The acid polymer of CNSL is rubber-like and has low susceptibility to oxidation. The polymerization time for CNSL in the presence of sulphuric acid is one of the specifications for CNSL.
Acids such as sulphuric acid (H2SO4), hydrochloric acid (HCl), paratoluene sulfonic acid (PTSA), etc.
#CASHEW NUT ADVANTAGES AND DISADVANTAGES FREE#
The unsaturation in the side chain can be the basis for addition polymerization using free radicals or ionic initiators. The presence of aliphatic side chains gives these resins increased hydrophobicity, which is a valuable property for many end-uses. CNSL can be polymerized by a variety of techniques. Polymerization is the most important reaction of CNSL from the point of its applications. It can replace phenol in many applications with equivalent or better results. It is a cheap and renewable substance and can be employed for the manufacture of a multitude of useful products. It is a naturally occurring substituted phenol which can take part in a variety of reactions. Massive literature is available on applications of cashew nut shell liquid.Ĭashew nut shell liquid (CNSL) is a by-product of the cashew industry. CNSL by itself is useful for insecticidal, fungicidal, and medicinal applications, and as an additive, in many plastic formulations. CNSL is used for the treatment of acne vulgaris. It is used traditionally as a cure for fungal attack of the feet in Kerala. It is used as a raw material to produce other derivatives which in turn have many different applications.ĬNSL is used in tropical folk medicine and for anti-termite treatment of timber. TABLE 2: CNSL SPECIFICATIONS OF AFRICAN COUNTRY CHARACTERISTICSĬashew nut shell liquid (CNSL) has a wide range of useful applications.
Slightly different CNSL specifications are used in another country (in Africa), as shown in the following table.
The following table lists Indian Standard Specifications for CNSL. The characteristics of this treated CNSL are different from the original, i.e., raw CNSL. CNSL produced by using cold press solvent extraction method needs to be treated to remove metallic impurities as well as traces of sulphur compounds. The present article discusses specifications and applications of cashew nut shell liquid (CNSL).Ĭharacteristics of cashew nut shell liquid (CNSL) obtained from different manufacturing processes vary to some extent.
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