Patent ID: 8192676

Claim:
A method, comprising: (a) forming a preblend comprising: (i) a diluent polyester, (ii) a polyamide material, wherein the polyamide material comprises a polymer containing m-xylylenediamine monomer units, p-xylylenediamine monomer units, or a mixture thereof, and (iii) cobalt or a complex or salt thereof present in the preblend in an amount of 20 to 2,000 parts per million, by weight; (b) providing a base polyester; (c) introducing the preblend of step (a) and the base polyester of step (b) into a molding apparatus to permit melting and admixing of the preblend and the base polyester; (d) injection molding or extruding the admixture of step (c) in the apparatus to provide a preform; and (e) expanding the preform of step (d) to provide a plastic container having a barrier layer formed from the admixture of step (c); (f) wherein the plastic container is stable during unfilled storage and the barrier layer has an oxygen scavenging property that is activated after filling the container with an aqueous fluid, and wherein activation results from filling.