Effect of surface treatment of a polymeric filler on its interaction with a plasticizer

The interfacial behavior of a filler–plasticizer system was investigated using the pair poly(sodium methacrylate-co-divinylbenzene) beads–diisooctyl phthalate. The effect of various surface treatments of the filler was studied. These consist of a selective extraction of surfactant used in its preparation by emulsion copolymerization and in the adsorption of other types of surfactants. Changes in the compatibility between the two basic components were determined from measurements of the rate of penetration of the plasticizer through the filler bed, from the rheological behavior of concentrated suspensions and from the extractability of the filler from the plasticized PVC matrix.