Polyoxyethylene Derivatives of Polyoxypropylene Cetyl Ether. II.

Abstract

To study an emulsifying character of the 16 derivatives of polyoxyethylene-polyoxypropylene cetyl ethers, O/W emulsions of mineral oil, selected as the standard oil phase, were prepared for emulsification tests by using the combined emulsifiers which consist of these derivatives and the standard emulsifier, varying the rate of combination of two emulsifiers.(1) HLB values of these derivatives were determined from the optimum emulsifying condition. Increase in the mole numbers of propylene oxide, P, in a molecule showed a tendency to become smaller HLB values, however an abnormally high HLB values were observed for the derivatives which involved smaller number of moles of ethylene oxide, E, in a molecule and larger mole number of P.(2) The HLB value of these derivatives which gave the excellent O/W emulsions of mineral oil, being the HLB value at 10.2, was roughly between 914.(3) From the temperatures observed for the completion of phase inversion from W/O to O/W, the phase inversion temperature at optimum emulsification was higher when the mole number of P is smaller and that of E larger. For the derivatives having same mole number of E, the temperature generally became lower when the mole number of P becomes larger. Inclination of curve in the diagram, phase inversion temperature vs. combination of two emulsifiers, showed a tendency to decrease with increase of the mole number of P in a molecule.