Bio‐based polymeric resin from agricultural waste,neem (Azadirachta indica) seed cake,for green composites

Protein‐based polymeric resin has been developed from nonconventional and nonedible “neem seed cake (NSC)” that has very limited low‐value applications. Neem protein (NP), after extraction from defatted NSC, was used to prepare resin with two common plasticizers (glycerol and sorbitol). Properties of the NP resin sheets were evaluated as a function of plasticizer content. Increase of plasticizer content in NP sheets from 15 to 30% (w/w) enhanced fracture strain with a reduction in tensile strength, modulus, and thermal properties. Sorbitol‐plasticized NP sheets showed better mechanical and thermal properties in comparison to glycerol‐plasticized sheets. Effect of cross‐linking with glyoxal on the mechanical and thermal properties of sorbitol‐plasticized NP sheets was also investigated. Properties improved significantly at 10% (w/w) glyoxal content. Overall, with the enhanced properties of NP sheets, NP can be a viable alternative for edible protein‐based resin for making green composites. NP resin can also be used to replace some synthetic resins. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 10.1002/app.41291.