Governments around the world have made several efforts to reduce this dependence on petrochemicals since it is a fast-depleting resource and has been a major cause for a variety of environmental issues. The “Green Chemistry” principles laid down in 1998 presented a guideline for researchers to curb environmentally harmful chemicals at source. One of these principles promotes the use of renewable feedstocks as an alternative to non-renewable ones such as petrochemicals.

As a result, there has been a surge in interest in the research community to find potential biomass candidates to develop bio-based materials. One such candidate that has garnered a lot of attention is Cardanol – obtained from an agro-waste of the Cashew Industry [2].

[1] “The Future of Petrochemicals: Towards a more sustainable chemical industry,” International Energy Agency (IEA) , Paris, 2018.
[2] P. T. Anastas, J. C Warner, “Green Chemistry: theory and practice”, New York, USA: Oxford University Press, 1998.

The cashew shell is a by-product of processing cashews and was earlier simply discarded as waste. It is a leathery substance that contains ~67% by weight a reddish-brown caustic and oily viscous liquid – Cashew Nut Shell Liquid (CNSL).

CNSL is a rich source of an assortment of phenolic compounds with unsaturated aliphatic chains. These include anacardic acid, cardol, cardanol and 2-methyl cardol. The composition of CNSL can vary based on geographical location of its source, but the final composition mainly depends on the method by which it is extracted.

Cardanol is NSPC’s platform raw material with most of our products comprising of > 60% of this bioderived phenolic monomer from CNSL. It is a pale yellow liquid and consists of a mixture of cardanol compounds that vary in the degree of unsaturation present in the meta positioned aliphatic side chain. The C₁₅ chain could be completely saturated or have a monoene, diene or triene.

The inherent properties of cardanol make it an ideal candidate to replace petroleum monomers. Cardanol has diverse and versatile functionalities which allow for its modification to suit a variety of applications. The long aliphatic chain at meta position imparts hydrophobicity, flexibility and low viscosity. Its low volatilization, high boiling point and absence of aggressive odours make handling, processing and storing unproblematic.

Our Cardanol-modified 2K Epoxy Resins are a greener alternative to commercially available Epoxy Resins in the market. With cardanol chemically incorporated in the Epoxy Resins, these show superior corrosion resistance, excellent adhesion, and good flexibility even at high DFT. These resins also require lower amounts of hardener thereby reducing cost of overall 2K Epoxy System. Switching to these resins, formulators can also eliminate expensive wetting agents as well as co-solvents such as butanol from formulations.

Phenalkamines are Cardanol-based epoxy curing agents. They exhibit rapid cure (even at subzero temperatures), moisture resistant curing, excellent corrosion resistance, chemical resistance, blush resistance and surface tolerance. NSPC offers a range of the lowest coloured Phenalkamines currently available in the market.

Our phenalkamides have been precisely engineered at a molecular level, whereby strong chemical bonds link amide and phenalkamine groups to ensure long lasting performance coatings. They demonstrate superior corrosion resistance, fast drying and moisture tolerance like Phenalkamines, while allowing for workable pot life comparable to Polyamides.