Preparation of Polyrotaxane Fibers. Part I: Influence of Dope Solvents on the Physical Properties of Wet-spun Polyrotaxane Fibers

The preparation of polyrotaxane fibers by wet spinning of polyrotaxane, consisting of poly(ethylene glycol) (PEG) and α-cyclodextrins (α-CDs), was examined using three different types of dope solvents: dimethylacetamide (DMAc) containing 8 wt% lithium chloride (LiCl), dimethylformamide (DMF) containing 8 wt% LiCl, and dimethylsulfoxide (DMSO). In DMSO, polyrotaxane concentrations of 20 and 30 wt% were favorable for the smooth spinning of fibers with sufficient tenacity, while other polyrotaxane concentrations (10, 15, and 40 wt%) were unsuitable for the wet spinning of durable fibers. All of the fibers had nearly identical scanning electron microscopy (SEM) images and X-ray diffraction patterns. Although the values for tenacity at break and initial modulus also were similar for all fibers, elongation at break of fibers from DMSO was higher than the values for the other two fibers. The poorer physical properties of the latter two fibers may be affected by the slight amount of lithium salt remaining in the fibers.