Abstract:

Polymeric surfactants, based on grafted polyethyleneglycol (PEG) with different chain lengths on polymethylmetacrylate (PMMA), have been prepared and studied. The `'stabilizing moiety'', PEG, was grafted by a transesterification reaction on the -OCOCH3 groups of the `'anchoring moiety'' PMMA, obtaining comb type substituted PMMA. The amphiphilic polymers reduce only slightly the water/air surface However, interfacial tension of certain `'oil phases'' such as toluene were significantly reduced. The best polymeric surfactant, reducing interfacial tension practically to zero, was PMMA of MW 130000 grafted with 6.5 wt% PEG consisting of 22 ethylene oxide (EO) units. Spontaneous emulsification was achieved with very low polymer concentration (\textless1.0%). Flocculation was observed in emulsion in which excess emulsifier was used or in systems containing free ungrafted PEG.