Enhanced tensile strength and initial modulus of poly(vinyl alcohol)/graphene oxide composite fibers via blending poly(vinyl alcohol) with poly(vinyl alcohol)-grafted graphene oxide

Poly(vinyl alcohol)-grafted Graphene oxide (PVA-g-GO) as novel nanofillers were used to reinforce poly(vinyl alcohol) (PVA) composite fibers via simple wet spinning to promote homogeneous dispersion of reinforcing nanofillers as well as strengthen interfacial adhesion between nanofillers and matrix. Then the impact of these PVA chains grafted above GO sheets on the compatibility and dispersion of PVA-g-GO sheets in PVA fiber, the interfacial adhesion between nanofillers and matrix and the structure as well as property of PVA-g-GO/PVA fibers were studied systematically via characterizing morphology, aggregation structure and mechanical property of these composite fibers. These results showed that not only well dispersion and compatibility of PVA-g-GO sheets in composite fibers could be achieved, but also obvious enhancement in interfacial adhesion between nanofillers and matrix. Meanwhile, significant reinforcement in tensile strength and initial modulus of these composite fibers could also be obtained. Compared with neat PVA drawn fiber, tensile strength and initial modulus of these composite drawn fibers could increase by 39% and 69% with addition of 0.60 wt% of PVA-g-GO sheets, respectively. On the one hand, crystallization and orientation degree of these composite fibers could be improved because of the template-oriented effect of PVA-g-GO sheets during hot drawing. On the other hand, efficient load transfer between matrix and nanofillers in composite drawn fibers could be achieved easily because of the strong interfacial adhesion between nanofillers and matrix. These were also two main reasons for the obvious improvement in tensile strength and initial modulus of composite drawn fibers.