Effect of impact modifier on the properties of poly (ethylene terephthalate)-organoclay nanocomposites

The effects of component concentrations and addition order of the components, on the final properties of ternary nanocomposites composed of amorphous poly (ethylene terephthalate) matrix, organically modified clay, and an ethylene / methyl acrylate / glycidyl methacrylate (E-MAGMA) terpolymer were studied. All formulations were prepared by melt compounding of the components with a two-step mixing procedure in a corotating twin-screw extruder. Considering the X-Ray Diffraction, SEM, impact and strain at break results, the best sequence of component addition was the one in which PET was first compounded with E-MA-GMA, later this mixture was compounded with the organoclay in a subsequent run. In this mixing order, the polymer-impact modifier matrix mixture prepared in the first extrusion run has higher melt viscosity than pure PET, thus this matrix can apply high shear stresses on the clay particles and delaminate the clay layers resulting in the best mechanical properties.