Plasticisation of Carnauba Wax with Generally Recognised as Safe (GRAS) Additives

The plasticisation of carnauba wax has been examined by adding generally recognised as safe (GRAS) molecules of branched structures in order to disrupt the orderly packed molecules within the wax. The effectiveness of a range of different potential GRAS plasticisers was assessed by mechanical characterisation based on flexural and indentation measurements to determine parameters such as flexural strain and stress, fracture energy and Young's modulus. The microstructures of fracture surfaces were analysed using scanning electron microscopy (SEM) and the fracture surface roughness was measured utilising white light interferometry (WLI). The melting behaviour and crystallinity were investigated using differential scanning calorimetry (DSC) and x-ray diffraction (XRD). It is shown that polysorbates are effective GRAS grade plasticisers. The performance of all the materials investigated is rationalised in terms of the underlying molecular mechanisms of plasticisation, which contributes to the fundamental understanding of the plasticisation of wax.