ABSTRACT
I. INTRODUCTION The term esterquat is commonly used to describe a family of cationic surfactant compounds that is heterogeneous in the chemical sense. In this chapter, we define esterquats as a class of surface-active quaternary ammonium compounds having the general formula R4N(+lx<->, characterized by the fact that the hydrophobic parts of the moieties "R" are linked to the charged head group via ester bonds R-C(O )0-or ROC(O )-, with x<-l being any anionic counterion. Somewhat arbitrarily, we further propose that any alkyl chain in a moiety R that contains more than four carbon atoms shall be considered as belonging to the hydrophobic part of the molecule. By application of this definition, an ester compound that contains a moiety R directly bonded to a cationic nitrogen, with R containing more than four carbon atoms, is not considered an esterquat.
