Cellulose Thermoplastics with Tunable Performance to Sustainable Plastic Substitutes.

The development of recyclable thermoplastic materials derived from natural sources is crucial in addressing the global plastic pollution problem. Herein, we used natural cellulose as a raw material to prepare a series of cellulose thermoplastics that are easy to recycle and have adjustable properties and excellent toughness through a homogeneous etherification process. The introduction of ether groups significantly weakens the hydrogen bonding interactions between cellulose chains, thereby facilitating the thermal motion of these chains. By changing the chemical structure and amount of ether groups, the glass transition temperature of cellulose ethers can be adjusted in the range 95-173 °C, and thermoplastic processing can be realized at 180-250 °C. The tensile strength of the obtained cellulose thermoplastics can be adjusted in the range 5-60 MPa, and the elongation at break can be adjusted in the range 15%-70%, which is much higher than the toughness of the reported cellulose thermoplastic materials and meets the performance requirements of common plastics. Moreover, they have an excellent water resistance. Even after long-term immersion in a high-humidity environment and water, the tensile strength remains basically unchanged and the toughness is slightly improved. Cellulose thermoplastics can be processed into various plastic forms such as water cups, straws, packaging materials, and fibers through common thermoplastic processing methods. Such high-performance thermoplastics based on natural polymers are expected to be a promising candidate for sustainable plastic.