Polyvinyl butyral‐zirconia hybrid hollow fibers prepared by air gap spinning

In this study, an air gap spinning method was adopted to develop polyvinyl butyral (PVB)‐zirconium (Zr) hybrid hollow fibers. With zirconium alkoxide, three kinds of PVB with different degree of acetalization were used as organic polymers. The morphologies, surface Zr content and relative bonding inside the hollow fibers were characterized by changing coagulation solution concentration, spinning dope viscosity and air gap distance. The effect of Zr on PVB structure were examined in terms of x‐ray photoelectron spectroscopy, scanning electron microscopy, thermogravimetric analysis and Fourier transform infrared spectroscopy. Results indicate that PVB spinning solution experienced good mixing mechanism at room temperature and immediately develop structural hollow fiber when extruded into coagulation fluid of Zr alkoxide by 2.0 cm air gap distance. Among other prepared fibers, fiber contained 20 wt% PVB with 2 cm air gap confirms effective average diameter of about 1016 μm which strongly influenced by spinning solution viscosity. The variation of maximum Zr content (8.18%–14.36%) confirms the asymmetry of coordinate bonding occurred on internal and external surface. Moreover, changing of spinning solution viscosity, coagulation liquid concentration and air gap can only affect the surface roughness and fiber diameter whereas no micro pores were developed in the fiber sublayers.