Surfactant interaction with HMHEC

Hydrophobically modified water-soluble polymers (HMWSPs) exhibit enhanced solution viscosity and unique rheological properties. These properties can be explained in terms of intermolecular associations via hydrophobes. This chapter describes the synthesis and solution properties of HMWSPs, Particularly discussed are the solution properties of hydrophobically modified hydroxyethytjcellulose (HMHEC) in aqueous and surfactant systems, HMHECs interact with surfactants and thus modify solution viscosities. The structure and the concentration of the surfactant dictate the solution behavior of HMHEC. The unique solution properties of HMHEC can be exploited to meet industrial demands for specific formulations or applications. 

Figure 16. Schematic of the molecular interactions between HMHEC and surfactant molecules below the critical micelle concentration. Reproduced with permission from ref. 10. Copyright 1987 TAPPI Press.)...

HMHECs can be viewed as polymeric surfactants. They tend to interact with low molecular weight surfactants and thus modify solution viscosity. The viscosity changes, however, depend on the nature (nonionic or ionic) and concentration of the surfactant. The molecular behavior of HMHEC in the presence of various types of surfactants has been described by Gelman (10) and Steiner (13). 

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