valeurs de contrainte d' ecoulement relativement plus faibles. La dilution de chaque formulation a provoqu e une d egradation de la viscosit e de chaque formulation, les formulations ayant la limite d' elasticit e la plus elev ee conservant une viscosit e plus elev ee que les autres formulations. Les formulations avec la limite d' elasticit e la plus elev ee dans chaque syst eme qui maintient egalement la viscosit e de dilution la plus elev ee (6% BTAC/10% CA et 6% CTAC/ 10% CA) a le meilleur effet sur la r eduction de la force de peignage globale, c'est-a-dire des cheveux secs aux cheveux mouill es tress ees et apr es que le produit soit rinc e. Dans un syst eme BTAC/CA de rapport 6: 5, il y a une r eduction de 89% de la force de peignage et une r eduction de 95% de la force de peignage dans le syst eme

The objective of this work was to carry out a comprehensive evaluation of the performance of a novel cationic amino lipid surfactant, Brassicyl Valinate Esylate (BVE), in contrast to conventional alkyl quaternary ammonium surfactants (quats), through a study of the effects of process mixing speed on its overall rheological, tribological and wet lubrication performance in comparison to BTAC and CTAC, two cationic surfactants widely used in cosmetics. The major cosmetic application of cationic surfactants is in the preparation of hair conditioners. Hence, this analysis was done firstly by conducting tensile combing tests to evaluate reduction in wet lubrication which translates to conditioning performance. The combing results serve as a testing metric that adequately corresponds to consumer perception of conditioned hair. To correlate this technically, yield stress measurements were conducted to establish rheologic profiles of the conditioner formulations, and in vitro tribological testing of the emulsion systems between two steel surfaces were done to technically simulate the spreading and rubbing of conditioner on the hair. The effect of processing conditions on the formulations was then evaluated. BVE was found to be an effective conditioning surfactant suitable as an eco-friendly replacement for BTAC and CTAC in hair conditioner formulations. The results showed that higher shear mixing rates during formulation lead to poorer performance effects evident through decreased yield stress values, lower percentage reduction in combing force and a higher coefficient of friction.