▎ 摘　　要

NOVELTY - Manufacture of modified phenolic resin-cellulose composite film involves crushing 10 g medical absorbent cotton, hydrolyzing with 50 wt.% sulfuric acid solution at 45 degrees C for 2 hours, adding cold deionized water, settling overnight, washing, centrifuging, dialyzing to obtain nanocrystalline cellulose suspension, dissolving phenol in sodium hydroxide solution, magnetically stirring at 40-42 degrees C for 10 minutes, adding formalin, stirring, cooling, neutralizing with hydrochloric acid aqueous solution, to obtain a viscous product, dissolving the product in ethanol, precipitating, filtering to prepare a phenolic resin precursor solution, ultrasonically treating nanocrystalline cellulose suspension for 15 minutes, adding the resin precursor solution and the graphene solution, stirring, mixing, drying, and thermally polymerizing to obtain a composite film, placing composite film in a beaker containing sodium hydroxide aqueous solution, heating, cooling, rinsing, and drying. USE - Manufacture of modified phenolic resin-cellulose composite film used in sensing, optical and safety applications. ADVANTAGE - The method enables manufacture of modified phenolic resin-cellulose composite film with excellent crack resistance, thermal stability, mechanical strength, hardness, rigidity and flexibility, and suppressed generation of defects. DETAILED DESCRIPTION - Manufacture of modified phenolic resin-cellulose composite film involves crushing 10 g medical absorbent cotton, hydrolyzing with 50 wt.% sulfuric acid solution at 45 degrees C for 2 hours, adding cold deionized water, settling overnight, washing thrice with deionized water to remove the dissolved cellulose in the water, decanting the supernatant, centrifuging, dialyzing the dialysis film having molecular weight of 12000-14000 until the pH is 2.4 to obtain nanocrystalline cellulose suspension, dissolving phenol in sodium hydroxide solution, magnetically stirring at 40-42 degrees C for 10 minutes, adding formalin at 50 degrees C, stirring at 70-75 degrees C for 1 hours, cooling to room temperature, neutralizing with 0.6 M hydrochloric acid aqueous solution, removing water by rotary evaporation at less than 50 degrees C to obtain a viscous product, dissolving the product in ethanol, precipitating, filtering to prepare a phenolic resin precursor solution, ultrasonically treating nanocrystalline cellulose suspension for 15 minutes, adding the resin precursor solution and the graphene solution, stirring, mixing, placing the mixture in a polytetrafluoroethylene tray, drying under ambient conditions for 36 hours, and thermally polymerizing in an oven to obtain a composite film, placing 200 mg composite film in a beaker containing 100 mL 16% sodium hydroxide aqueous solution, heat-stirring, cooling to room temperature, rinsing with deionized water until the pH is neutral, and drying at room temperature.