Preparation and characterization of polyaniline/natural rubber composite fibers

Abstract

Polyaniline/natural rubber composite fibers were fabricated by a wet spinning method. Latex dopes for spinning contained three components, i.e. natural rubber (NR) latex, polyaniline (PANI) and sodium alginate (viscosity controller). PANI content in the composite fibers was varied from 0 to 10% (w/w). After extrusion through a spinneret, the neat fiber bundles were passed into two coagulation baths containing calcium chloride/methanol and methanol, respectively. The composite fiber bundles were immersed into an HCI solution to achieve the PANI emeraldine salt form (ES), the conducting state form. The effects of PANI content on the electrical conductivity and mechanical properties of the bundles of composite fibers were investigated. SEM micrographs of the cross-sectional morphology of the composite fiber bundles revealed that PANI particles were inhomogeneously distributed in the natural rubber matrix. When PANI content increased from 0 to 10% (w/w), the electrical conductivity of the fibers increased from 10-10 to 10-3 S/cm, whereas the tensile property decreased from to 1 to 0.35 cN/tex. However, the elongation at break decreased from 820 to 600%, indicating that these composite fibers still retained the elastomeric property of natural rubber for all compositions. The electrical conductivity of bundles of the composite fiber was preserved upon elongational deformation even if strains as large as 600% were applied. The bending deformation of the composite fiber under electric field demonstrated that the composite fibers can be further developed for soft actuator application.