Bis-PMMA/Polybutyl Acrylate Copolymer is a nitroxide-endcapped triblock copolymer of Butyl Acrylate and Methyl Methacrylate. It is prepared by nitroxide-mediated controlled radical polymerization, wherein a difunctional initiator is used to first prepare a center block of Polybutyl Acrylate followed by further reaction with Methyl Methacrylate to form Polymethyl Methacrylate blocks on both ends of the Polybutyl Acrylate. It is chain terminated with ethyl phosphinate as shown in the formula: