Patent ID: 8461225
Filing Date: 2013-06-11
Classification: C08J,Y02P

Abstract:
1. A method of making an antioxidant-doped homogenized cross-linked polymeric material comprising: a) irradiating a consolidated polymeric material at temperature below the melt with ionizing radiation; thereby forming a cross-linked consolidated polymeric material, wherein the polymeric material is selected from the group consisting of a low-density polyethylene, high-density polyethylene, linear low-density polyethylene, ultra-high molecular weight polyethylene (UHMWPE), Nylon, polyethylene terephthalate (PET), polyether-block co-polyamide polymer, co-polymers of polyether and polyamide, Polyam ides, Polyesters, ethylene vinyl alcohol (EVA), polyvinyl chloride (PVC), polyurethane, polyolefins, thermoplastic elastomers, polyamide/imide, polyester, polycarbonate, and fluoropolymers; b) doping the cross-linked consolidated polymeric material from step a) with an antioxidant by diffusion at ambient pressure without using a supercritical fluid; and c) annealing the antioxidant-doped, cross-linked polymeric material from step b) at a temperature below the melt in a supercritical fluid for 4 hours to several weeks; thereby allowing diffusion of the antioxidant into the polymeric material and forming an antioxidant-doped homogenized cross-linked polymeric material, wherein annealing in presence of the supercritical fluid increases the diffusion rate and depth of penetration of antioxidant into the polymeric material.