Polyethylene terephthalate graft copolymers acting as an interfacial modifier in rubber modified polyethylene terephthalate compounds

Compounding rubbery materials into polyethylene terephthalate (PET) alone is not sufficient to absorb and dissipate impact energy at sub-ambient temperatures. A PET-graft-rubber additive made by reactive extrusion acts as an interfacial modifier providing a mechanism for stress transfer from the PET matrix component to the dispersed rubbery component. The chemical structure verification of the graft copolymer and its effect on properties were established. Improvements in low temperature toughness and impact strengths are presented for containers thermoformed from extruded sheet.