Decoloured Novatein® and PLA Blends Compatibilized with Itaconic Anhydride

Abstract

Poly (lactic acid) (PLA) was modified through free radical grafting of itaconic anhydride to create reactive side-chain groups. Modified PLA was blended with Decoloured Novatein®(DNTP), a thermoplastic protein material using reactive extrusion to produce a degradable material with improved properties compared to neat Decoloured Novatein®. Varying ratios of blends were prepared. Blending DNTP with PLA was found to increase tensile strength between 22% to 538% and modulus between 201 GPa to 3193 GPa, whereas the strain at break decreased between 80% to 94% depending on the blend ratio. The glass transition temperature of the blends which was measured as the tan δ peak, also revealed an increase when compared to neat DNTP. Scanning electron microscope revealed an enhanced interfacial adhesion between the two phases in the blends with PLA-g-IA suggesting a more homogenous microstructure. The results show the possibility and feasibility of blending DNTP with PLA for use in agricultural and packaging applications.