the present invention provides for polymeric stabilizers which are the acid - catalyzed reaction product of a phenolic compound or a ring substituted aromatic compound and an olefin polymer containing either terminal unsaturation and / or pendant unsaturation along the polymer chain . these stabilizers are readily compatiable with olefin polymer and copolymer matrixes and offer good protection of the matrix polymer against one or more of heat , oxygen , ultra violet or radiation degradation . other advantages include low volatilization as well as low tendency to migrate from the polymer matrix .