Hair Expansion Effect of Dodecyl Trimethyl Ammonium Chloride and Its Application to Hair Care Products

Abstract

Cationic surfactants are formulated in various hair care products, including hair treatments, because they tend to smooth the hair's surface through adsorption. Many studies have been reported on the adsorption behavior of cationic surfactants on the hair's surface, as well as their effects on the hair. On the other hand, while it is also known that cationic surfactants penetrate into the hair, few studies have investigated their effects on the hair. Therefore, we investigated the effects of permeating the cationic surfactant alkyl trimethyl ammonium chloride into the hair. As a result, we found that alkyl trimethyl ammonium chloride has the effect of expanding hair. Further experiments found that dodecyl trimethyl ammonium chloride (DTAC) with an alkyl chain length of 12 is highly effective at expanding hair in a short treatment time. From a quantitative analysis of DTAC in hair, we clarified that the hair expansion by DTAC mainly results from the large amount of DTAC absorbed into the hair. In addition, hair treated with DTAC showed an increase in flexural rigidity and a repair of the distorted cross-sectional shape caused by damage. These results suggest that DTAC has great potential for future hair care products.