• Improved Flexibility and reduced brittleness.
• Solubility in Organic Solvents.
• Improved Processability.
• Low Fade Characteristics for Friction.
• Resistance to 'Cold Wear'.
• Good Electrical Resistance.
• Better Water Repellence.
• Improved alkali and acid resistance.
• Compatibility with other polymers.
• Antimicrobial Property.
• Termite and Insect Resistance.
• Structural Features for Transformation into High Performance Polymers.
  

      CNSL can be polymerised by a variety of methods:

• Addition Polymerisation through the side chain double bonds using cationic initiators such as sulphuric acid, diethylsulphate etc..
• Condensation Polymerisation through the phenolic ring with aldehydic compounds.
• Polymerisation after Chemical Modification to introduce speciality properties.
• Oxidative Polymerisation.
• Various Combinations of the above.
  

• Low Cost Phenol.
• Versatility in Polymerisation and Chemical Modification.
• Possibilities for Development of High Performance Polymers.
• Property advantage over phenolics in certain applications such as impact resistance, flexibility, faster heat dissipation etc.
   
  

CNSL undergoes all the conventional reactions of phenols. Cardanol differs from phenol only in the C15 side chain. It undergoes the well known formaldehyde condensation reaction of phenols that gives rise to phenolic polymers. Moreover, it can be polymerised through the unsaturation in the side chain although the bulky nature of the side chain restricts the molecular weight attainable to oligomers. One of the significant advantage of the cardanol is its amenability to chemical modification to effect desirable structural changes so as to get specific properties for making tailor-made polymers of high value. Thus, structural changes could be effected at the hydroxyl group, on the aromatic ring and on the side chain.

Distillation of CNSLunder reduced pressure gives cardanol. The residue will be rich in cardanol and is generally known as residol, which is conveniently used in the preparation of friction dust for brake linings, and also in rubber compounding formulations. ( The process know-how for the production of cardanol and conversion of residol into friction dust is available with RRL, Thiruvanathapuram).

Specific Gravity/30° C	0.950 - 0.970
Viscosity at 30° C cps, Max.	550.0
Moisture % by weight, Max.	1.0
Matter Insoluble in Toluene % by weight, Max.	1.08
Loss in Weight on heating, % by Weight, Max	2.0
Ash % by weight, Max.	1.0
Iodine Value, Min	1.0
1. Wij's method	250
2. Catalytic method	375
Polymerisation Time
a) Time in minutes, Max.	4
b) Viscosity at 30° C, cps, Min	30
c) Viscosity after acid washing at 30° C cps, Min	200
Color shall be not deeper than dark brown when viewed by transmitted light.

The cashewnut shell liquid as extracted has a strong vesicant dermatatic action.   Before this liquid is utilized for preparation of resins,  it requires treatment to get rid of metallic impurities as well as traces of sulphur compounds.   The liquid thus treated is known as " Treated Cashewnut Shell Liquid ".
The specification of treated cashewnut shell liquid is as follows:

Specific Gravity at 25° C / 24° C	0.955 - 0.975
Viscosity at 25° C ( max.)	800 cps
Lodine Value ( min. )	240.00
Ash ( max )	1%
Moisture ( max. )	0.5%
Acid Value ( max. )	14

Cashewnut shell liquid is also produced by the 'Cold Pressed' method in solvent extraction plant. The specification of the liquid is as follows:

Specific Gravity at 26° C	0.9668 - 1.0131
Refractive Index at 41.50° C	1.5158
Saponification number	106 - 119
Iodine number	270 - 296
Acid number	94 - 107