An alternative approach to dealing with the PET compatibility issue was devised in Amoco Chemicals (Cahill and Chen, 1997). This approach involved making a block copolymer of a polybutadiene with PET with the trade Amosorb^TM 3000, sold by BP Amoco. The PET caused the compatibilization while the polybutadiene was the oxidizable polymer. The process is catalyzed by means of a transition metal salt. This polymer lent itself to use in PET bottle manufacture, since the catalyst can be added at a late stage in the injection-molding process and premature oxidation can be minimized. Even though the injection-molded preforms have been heated while containing the catalyst, they have a substantial shelf life due to the low permeability of the thick layer of PET, especially when the Amosorb^TM3000 is in a buried layer. Perhaps an improvement would be to include some form of triggering or activation closer to the time of filling the bottle.