In this study, waste cotton fibers were environmentally reused. First, they were milled into fine powders with particle sizes of around 30 µm and dyed for use as pigments. Dyeing properties of the cellulose powder were explored by determining the dye uptake, K/S value, and bath ratio. Among the various samples, powders with owf (on weight of fabric) of 0% dye (pristine cellulose powder), and 10% and 50% dyed powders were selected; and these powders were characterized by several methods to compare the properties of dyed and undyed cellulose. The surface morphologies of the powders were observed with a scanning electron microscope (SEM). Combining the SEM images with the Brunauer-Emmet-Teller (BET) data, it was found that the smaller the particle size, the larger is the surface area. In addition, the X-ray photoelectron spectroscopy (XPS) results revealed that with increasing dye concentration, the intensity of the C peak reduced, while those of O and S increased. Moreover, the main components of the dyed and undyed cellulose powders were found to be almost the same from the Fourier-transform infrared spectroscopy (FTIR) results. Finally, the dynamic mechanical analysis (DMA) data revealed that the loss modulus was significantly larger than the storage modulus, demonstrating that the material mainly undergoes viscous deformation.
Keywords: DMA; cellulose powder; dyeing properties; recycling of waste cotton; specific surface area; thermal analysis.