Abstract:

The structural evolution and performance behavior of a hair conditioner model formulation, emulsified at two different temperatures （65 and 80 ℃） and monitored during subsequent room-temperature storage, were systematically investigated via techniques including cryo-SEM, DSC, rheology, and combing tests. The results demonstrate that the emulsion processed at 65 ℃ forms a highly ordered lamellar sheet structure, which exhibits significantly superior bulk viscoelasticity and wet-hair combing performance compared to the mixed vesicle-lamellar sheet structure formed at 80 ℃. Following 15 days of room temperature storage, samples prepared at 80 ℃ undergo spontaneous reorganization of the vesicular structures, characterized by fusion, an increase in size, and a tendency to flatten and form continuous lamellar sheets. These findings indicate that the emulsification temperature is a critical factor governing the phase structure and performance of the system. Specifically, the 65 ℃ process facilitates the formation of a structurally stable lamellar sheet structure with excellent properties. Room-temperature storage drives the transition from a metastable vesicular state towards the stable lamellar sheet state, thereby elucidating the kinetic mechanism behind the observed enhancement in sensory performance upon storage. This study provides new insights into the development and production of high-performance hair conditioners.

Key words: conditioner, emulsification temperature, phase structure, rheological properties, behentrimonium chloride