Effects of the coagulation temperature on the properties of wet-spun poly(vinyl alcohol)-graphene oxide fibers

Graphene oxide (GO) as a positive reinforcement filler was dispersed into a poly(vinyl alcohol) (PVA) dope and wet-spun into composite fibers. The effects of two EtOH coagulation baths maintained at -5 and 25 degrees C, respectively, on the morphology, structure, and mechanical properties of the composite fibers were investigated. The results show that gel spinning at -5 degrees C led to a relatively large shrinkage ratio, thin diameter, and low porosity of the as-spun fibers. Simultaneously, the low coagulation temperature also greatly contributed to the formation and preservation of the liquid-crystalline phase of the GO sheets and interrupted the crystalline zone of PVA less. As a result, either the tenacity or the elongation at break of the fibers spun at -5 degrees C was higher than those of the fibers spun through a coagulation bath at 25 degrees C. In particular, 1 wt % GO showed the highest reinforcement effects among all of the wet-spun composite fibers. Hence, controlling the gelling-demixing process at a low temperature will provide more instructive insights for tailoring functional industrial textiles with excellent mechanical properties. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45463.