The maleic anhydride was used to prepare the MNR and another type of blend compatibilizer; the graft copolymer of HDPE and maleic anhydride (HDPE-g-MA) was manufactured by Riedel-de Haen, Seelze, Germany. Stannous chloride, used as a catalyst in the phenolic curing system, was manufactured by Fluka Chemie (Buchs, Switzerland). The polyphenolic additive, Wingstay® L, used as an antioxidant, was manufactured by Eliokem Inc. (Ohio, USA).