The behaviour of cationic cellulose derivatives containing fatty quat groups

Summary The use of trimethyl quat cellulose derivatives in hair and skin care products is well established. The introduction of fatty quat groups into cellulose can modify the surface activity and conditioning behaviour. The present study was directed to a coconyl dimethyl quat derivative of cellulose, with an average molecular weight of approximately 100,000. A modified version of the rubine dye test, capable of giving quantitative results, was used to seek information on substantivity and tendency for build-up on hair. The evidence presented indicates that this surface-active cellulose polymer exhibits a plateau maximum value for substantivity which is achieved by a single conditioning treatment as an aqueous solution with a concentration of 1% or higher. The same plateau value can be approached by successive shampoo/conditioning cycles at lower polymer concentrations. This in-built mechanism for preventing excessive build-up from aqueous solutions is compared with the behaviour of other cationic cellulose polymers of higher average molecular weight.