Molecular weight dependence of the physical properties of protonated polyaniline films and fibers

Abstract

Polyaniline, (PANT) in the form of emeraldine base (figure 1), was synthesized by polymerizing aniline in acid solutions at different sub-zero temperatures to give a range of molecular weights between 100,000 and 300,000 gmor1. Molecular weights were measured using gel permeation chromatography (GPC). The polymers were formed into solvent-cast films using an acid processing technique, involving 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPSA) as the solvating/protonating acid group and dichloroacetic acid (DCA) plus formic acid (FA) as the solvent. The dried, free-standing films were stretched by drawing over a hot pin to align the polymer chains. Fibers were prepared by spinning more concentrated solutions into a butanone coagulation bath. Conductivity measurements were then made on the drawn films and fibers, and tensile test measurements performed to determine the peak stress and modulus of the drawn films and fibers. The reaction conditions under which the different polyanilines were synthesized, and their molecular weight, were found to have a definite effect upon both the electrical and mechanical properties of the drawn films and fibers. The drawn films and fibers can be used as mechanical actuators.

Conjugated Polymer Actuators for Biomedical Applications

“…Despite the considerable work that has gone into chemically synthesizing PPy, as summarized by Wallace et al [6] (including a method claimed to produce soluble PPy [275,276] that should be spin-coatable), no actuators have yet been reported using these materials, nor have their mechanical properties been reported. Polyaniline has the advantage that it can be chemically synthesized and solution processed into films and fibers, which is being done commercially by Santa Fe Science and Technology, Inc. [52,208,209,230,277] Work still needs to be done, however, to quantify and understand the effects of processing parameters on material properties and actuator metrics. [278] Another actuator design issue is that of electroding the polymers.…”

State-of-the-Art Organic- and Inorganic-Based Hollow Fiber Membranes in Liquid and Gas Applications: Looking Back and Beyond

“…A comprehensive review of conductive polymer-based membranes for gas separation application was reported recently [ 117 ]. Noteworthy, Mattes’ group had conducted a few preliminary studies on conductive polymer fibers [ 493 , 494 , 495 , 496 , 497 , 498 , 499 , 500 , 501 ]. Nevertheless, research reported on conductive polymer-based hollow fiber membranes for gas separation is relatively limited, ascribed to the challenges such as low permeability, poor mechanical strength, poor solubility in common solvents, and easy agglomeration of fillers within the polymer matrix.…”

Ti3C2 MXene/Polyaniline/Montmorillonite Nanostructures toward Solvent-Free Powder Coatings with Enhanced Corrosion Resistance and Mechanical Properties

“…Polyaniline (PANI) is a well-known anti-corrosion filler among conducting polymers. It stems from the remarkable features of PANI, which include excellent chemical stability, adjustable conducting properties, and practical passivation capabilities. − Li et al successfully synthesized Ti 3 C 2 MXene@PANI composites by anchoring PANI to the surface of Ti 3 C 2 MXene nanosheets using in situ intercalation polymerization. They discovered that the synergistic impact of the barrier effect of Ti 3 C 2 MXene and the passivation effect of PANI resulted in a reduction in electrical conductivity along with excellent corrosion resistance in waterborne epoxy coatings.…”