AN OVERVIEW OF THE PREPARATION AND USE OF EMULSION POLYMER PARTICLES FOR THE TOUGHENING OF PLASTICS

The rationale for rubber-toughening of brittle plastics is presented together with a discussion of the advantages of using pre-formed toughening particles prepared by emulsion polymerisation. Rubber-toughened acrylic and epoxy resin materials ate used to illustrate the preparation and use of pre-formed emulsion polymer particles for toughening. For both types of material, tensile properties are controlled by the volume fraction of rubbery polymer, essentially independent of the size and morphology of the toughening particles. However, under the additional constraint ahead of propagating cracks, toughening particle size and morphology are shown to be important, and to have different effects in the two types of material due to inherent differences in the mechanism of yielding of the matrix polymer.