The influencing mechanism of thermo-oxidative aging of waste cotton textiles on mechanical properties of their regenerated fibers.

Recycling and reuse of waste cotton textiles reduces environmental pollution and lowers energy consumption. Presently, researchers have conducted a lot of studies on the reuse of waste cotton textiles, but there are fewer studies on how the degree of their aging affects the properties of the regenerated fibers. In particular, the higher the degree of aging, the greater the change of physical and chemical properties of them. In this paper, ionic liquids were used to dissolve cotton textiles with different degree of aging, and the effect of aging degree of cotton textiles on the viscosity of spinning solution was investigated. The regenerated fibers were produced using wet spinning, and their mechanical and chemical properties were characterized. When comparing regenerated fibers made from unaged cotton textiles with those made from cotton textiles aged at 200 °C, the tensile strength of the regenerated fibers decreases from 204.83 MPa to 47.50 MPa. By molecular dynamics simulation, the aging process of cotton textiles under different temperature conditions was explored, at high temperatures, cellulose molecular chains break, resulting in reduced mechanical properties. Therefore, selecting waste cotton textiles with the appropriate degree of aging based on the recycling purpose can facilitate the efficient use of waste textiles.