Green and efficient utilization of cellulose by in situ regenerating rod‐like cellulose crystals in dry blending rubber compounds

Abstract The crystalline cellulose has captured much attention as reinforcement material in rubber composites, but no successful cases have been found till now. Here, a facile approach of cellulose utilization was proposed by in‐situ regenerating cellulose in dry rubber matrix. Cellulose was dissolved in ionic liquid (IL), and then directly mixed with dry rubber, silica, and other ingredients. Taking advantages of the strong interaction between IL and silica, the dissolution equilibrium of cellulose/IL was destroyed and resulted in the regeneration of cellulose crystals in rubber matrix. The regenerated cellulose appeared at dry blending stage, and showed an ideal rod‐like shape (10–100 nm in diameter and 200–500 nm in length). While it grew in size at curing stage, and finally reached 100–200 nm in diameter and 1–2 μm in length. The regenerated cellulose exhibited pronounced reinforcement efficiency. This methodology has no any waste liquid discharged, and has a promising use in the preparation of cellulose/rubber composites. Highlights Nanosized rod‐like cellulose was regenerated in dry rubber, instead of latex. Regeneration of cellulose was due to interaction between ionic liquid and silica. The in situ regenerated cellulose dispersed well in cured rubber compounds. The regenerated cellulose exhibited a good reinforcement efficiency in rubber. The whole machining process had no any waste liquid discharged.