▎ 摘　　要

NOVELTY - Preparing high-strength graphene toughened polyacrylic acid hydrogel composite material involves adding graphite and sodium nitrate to the concentrated sulfuric acid solution, placing in a constant temperature reaction device, adding potassium permanganate at 0-5 degrees C, activating the reaction at low temperature for 20-60 minutes, heating up to 30-40 degrees C, and oxidizing at medium temperature, reacting for 20-60 minutes, then heating to 90-100 degrees C, reacting at high temperature for 5-20 minutes, filtering, washing, dialysis purification and freeze-drying to prepare graphene oxide with high oxidation degree, adding high oxidation degree graphene oxide and tea polyphenols into the distilled water solvent, disperse uniformly by ultrasonic and heating to 50-80 degrees C. USE - Method for preparing high-strength graphene toughened polyacrylic acid hydrogel composite material. ADVANTAGE - The method enables to prepare high-strength graphene toughened polyacrylic acid hydrogel composite material is good for improving the water absorption and water retention of the hydrogel material, avoids the graphene nano-particles are agglomerated and enhances the tensile strength and elongation at break of the hydrogel. DETAILED DESCRIPTION - Preparing high-strength graphene toughened polyacrylic acid hydrogel composite material involves adding graphite and sodium nitrate to the concentrated sulfuric acid solution, placing in a constant temperature reaction device, adding potassium permanganate at 0-5 degrees C, activating the reaction at low temperature for 20-60 minutes, heating up to 30-40 degrees C, and oxidizing at medium temperature, reacting for 20-60 minutes, then heating to 90-100 degrees C, reacting at high temperature for 5-20 minutes, filtering, washing, dialysis purification and freeze-drying to prepare graphene oxide with high oxidation degree, adding high oxidation degree graphene oxide and tea polyphenols into the distilled water solvent, disperse uniformly by ultrasonic and heating to 50-80 degrees C, reacting for 10-20 hours, centrifuging, washing and drying to prepare tea polyphenol modified graphite, adding tea polyphenols to modify graphene in distilled water solvent, adding initiator potassium persulfate after uniform ultrasonic dispersion, stirring and activating for 2-4 hours at 0-5 degrees C, slowly adding acrylic acid and acrylamide dropwise, adding hydrogen. The neutralization degree of the sodium oxide control solution is 80-90%, heated to 75-85 degrees C, reacted for 20-40 minutes, then added the crosslinking agent N,N-methylenebisacrylamide, reacted for 3-5 hours, filtered and washed, dialysis purification and freeze drying to obtain product.