FAQ
How can I determine the appropriate balance of an emulsifier pair (emulsifier A and emulsifier B) in EC formulation?
The simplest approach is to prepare two samples of the test formulation (premix A and premix B). The premix should contain a member of the pair at an arbitrarily fixed quantity (usually 5% or 10%). Blends of the premixes in different ratios (0:5, 0.5:4.5, 1:4,…) are then tested preferably at practical dilutions with water of given hardness. After this initial screening is completed, more accurate ratios may be selected for optimum performance.
TOP
As a first approach, it is necessary to carry out trials with surfactants having the same or similar HLB values. HLB is a useful but not sufficient tool. Without preliminary trials, it is difficult to find suitable alternative surfactants. In the case of EC, the HLB system is particularly helpful.
TOP
Vegetable oils are a complex mixture of esters of fatty acids containing large molecules, while mineral oils don’t contain ester linkages and molecular weights are relatively smaller. Concerning chemical structures, the emulsifiers must have structures which are similar to oils, e.g. ethoxylated vegetable oils can be used with success for triglycerides (according to Busagh-Ostwald continuity theory).
TOP
