A melt-processable, impact modified copolymer of acrylonitrile and methylacrylate typically containing 60 - 70% of acrylonitrile. It was developed to combine the excellent barrier properties of acrylonitrile (not melt-processable as a homopolymer) with melt processability. In addition to good barrier properties - better than PA and PET though not as good as PVDC - it has good chemical resistance and is used for a wide range of packaging applications.