▎ 摘　　要

NOVELTY - Preparation of a hollow sealing ring involves (i) extruding graphene/high silicon modified ethylene propylene diene monomer (EPDM) rubber, high elastic ethylene propylene rubber and phase change material (I) to obtain a strip embryo, (ii) extruding a phase change material (II) to obtain a phase change material segment, (iii) enclosing the strip embryo into a mold, (iv) arranging two temperature-blocking plates in the mold equipped with the strip-shaped embryo, placing the mold with the strip embryo in the oven, (v) heating, vulcanizing the materials in the drying room, and exporting the liquefied phase change material (I), (vi) stopping heating, and cooling down to obtain a treated strip-shaped embryo, (vii) cleaning the unvulcanized area, loading the phase change material segment into the treated strip embryo to obtain an embryo material, (viii) clamping the sealing ring with a mold, and (ix) opening the mold, removing the phase change material section, and trimming the edges. USE - Preparation of hollow sealing ring for passage door of main equipment of sodium-cooled reactor e.g. nuclear island device of nuclear island factory. ADVANTAGE - The leakage rate of the hollow sealing ring in the sealing test process is lower than 0.1sccm, and the technical requirement of the sealing ring for nuclear power is satisfied. DETAILED DESCRIPTION - Preparation of a hollow sealing ring involves (i) extruding graphene/high silicon modified ethylene propylene diene monomer (EPDM) rubber, high elastic ethylene propylene rubber and phase change material (I) to obtain a strip embryo, (ii) extruding a phase change material (II) to obtain a phase change material segment, (iii) enclosing the strip embryo into a mold, making the two free ends of the strip-shaped embryo body abut and closing the mold, (iv) arranging two temperature-blocking plates in the mold equipped with the strip-shaped embryo, and locating the two temperature-blocking plates are respectively on both sides of the abutting portion, placing the mold with the strip embryo in the oven, making the portion of the two temperature shields comprising the abutment located outside the oven, (v) heating, vulcanizing the materials in the drying room, and exporting the liquefied phase change material (I), (vi) stopping heating, and cooling down to obtain a treated strip-shaped embryo, which comprises a vulcanized area and an unvulcanized area, (vii) cleaning the unvulcanized area, loading the phase change material segment into the treated strip embryo to obtain an embryo material equipped with the phase change material segment, encircling and placing the embryo material containing the phase change material section in a mold for a sealing ring, (viii) clamping the sealing ring with a mold, and keeping at a temperature of 160℃ for 2-4 hours, and (ix) opening the mold, removing the phase change material section, and trimming the edges to obtain the hollow sealing ring. The cross section of the strip-shaped embryo comprises a central portion, an inner layer portion and an outer layer portion. The inner layer portion is sleeved on the outside of the central portion. The outer layer portion is sleeved outside the inner layer portion. The central portion is the extrusion portion of the phase change material (I). The inner layer portion is a high-elasticity ethylene-propylene rubber extrusion portion. The outer layer portion is a graphene/high silicon modified EPDM extrusion portion.