Effect of cationic charge and hydrophobic index of cellulose-based polymers on the semipermanent dyestuff process for hair

Synopsis In this work, the effects of a new class of polymers generally used in hair and skin cleansing products, the SoftCAT (SofCAT SL and SoftCAT SX), on the dye uptake on the hair fibre and the fading effects has been studied. These polymers, based on quaternary ammonium salts of hydroxyethylcellulose, are cationic products that differ in viscosity, hydrophobic substitution index (HS) and/or cationic substitution (CS, % N). UV-Vis spectroscopy has been used to analyse the extracted dyes from the hair cuticle and the cortex. The results indicate that the presence of polymers in the dye bath improve both the quality of the dyeing process and the anti-fading effect during the washing cycles. This phenomenon is postulated to be attributable to the polymers hydrophobically bonding with the dyes and so facilitating their increased penetration into the hair.Resume Les effets de nouvelles classes de polymere, generalement employees dans les produits de nettoyage de cheveux et de peau pour conditionner, le SoftCAT SL et SoftCAT SX sur la prise de colorant sur la fibre de cheveux et l'effacement de couleur apres un colorant semi-permanent, ont eteetudies. Ces polymeres, bases sur des sels d'ammonium quaternaire de hydroxyethylcellulose sont des produits cationiques qui different dans la viscosite, l'index hydrophobe de substitution (HS) et/ou la substitution cationique (CS, % de N). La spectroscopie d'UV-Vis a ete employee pour analyser les colorants extraits de la cuticule et du cortex de cheveux. Les resultats indiquent que la presence des polymeres dans le bain de teinture ameliorent la qualite du processus de teinture et l'effet antifading pendant les cycles de lavage. Ce comportement doit etre imputable aux possibilites des polymeres pour etablir l'interaction hydrophobe avec des colorants et ainsi pour faciliter le transfert de colorants a l'interieur des cheveux.