Study On MWNT/PVA Composite Fiber

Poly (vinyl alcohol) is a polyhydroxylated polymer with excellent performance and extensive usage. PVA was applied widely in fields of fiber, membrane, adhesive and biomaterial because of its good compatibility, film-forming property, fiberizability, cohesiveness and outstanding mechanical property. Especially, it was used as reinforced material in recent years. Carbon nanotubes(CNT) are the typical one dimension materials with outstanding mechanical, electrical, magnetic and thermodynamic properties. Research on the performance of polymer doped with CNT possesses values both in theory and application. The critical issue of the preparation of CNT/polymer composite material was the dispersion of CNT in polymer matrix. In this paper, the MWNT/PVA composite fiber was obtained by wet-spinning method. The work was summarized as follows:(1) Three methods, covers acidic treatment, surfactant treatment and adjusted pH value of solution were used to improve the dispersion of MWNT in polymer matrix. The results showed that MWNT was functionized due to the properly acidic treatment. The dispersion of MWNT in water was more stable owing to the adjusted pH value. PVA0588 have the best dispersibility according to the evaluation of three surfactants.(2) The MWNT/PVA composite solution was obtained through two steps: at first MWNT aqueous solution was prepared, and then PVA granules were dissolved in MWNT aqueous solution. The dissolved process of PVA was affected by the addition of MWNT. The MWNT/PVA composite membrane was cast and its properties, such as morphology and mechanical property were discussed.(3) The process of wet spinning of MWNT/PVA solution was studied. The dynamic rheological behavior of MWNT/PVA solution was investigated, indicating that the system showed shear thinning. The addition of MWNT reduced the complex viscosity, storage modulus and loss modulus of composite solution. According to the property MWNT/PVA composite solution and the issue of wet spinning process, the wet spinning machine were redesigned.(4)The morphology, structure and properties of MWNT/PVA composite fiber which was produced by wet spinning were studied. FESEM image confirmed the homogeneous dispersion of MWNT in PVA matrix. The addition of MWNT improved the mechanical property; with the 0.4wt% MWNT loading, the strength increased 71% than pure PVA fiber, while the mechanical and thermal properties were improved.