Numerous delicate parts of automobiles, medical devices, and other advanced technology are kept together by electrically conductive polymers like polyaniline.
A significant obstacle has prevented the synthesis of polyaniline for industrial electronics applications for a number of decades: which solvent makes the process the easiest?
In order to reduce the expense and complexity of producing polyanilines and to enable beneficial features like shape, it is crucial to address this abstract question. Up until now, it had been impossible to use a variety of inexpensive, low-boiling-point solvents, which would have substantially aided flexible polymer processing modes like inkjet printing.
Researchers from the University of Tsukuba and cooperating partners recently published a paper in Polymer-Plastics Technology and Materials in which they produced polyaniline in a variety of common solvents. With better processing and synthesizing capabilities, polyaniline manufacturing will be much simpler and more affordable.
“Polyaniline is an extremely versatile polymer in routine and advanced technologies, but restrictions on which solvents can be used for synthesis have long hindered this versatility,” explains Professor Hiromasa Goto, senior author. “Our discovery of how to facilitate polymerization in diverse solvents will be useful in basic research and industrial applications.”
When they added a modest amount of iodine to the reaction mixture, the researchers were able to convert aniline sulfate into polyaniline in a single step. This technique was compatible with a variety of solvents, including non-toxic ethanol and dichloromethane.
Polyaniline is an extremely versatile polymer in routine and advanced technologies, but restrictions on which solvents can be used for synthesis have long hindered this versatility. Our discovery of how to facilitate polymerization in diverse solvents will be useful in basic research and industrial applications.
Professor Hiromasa Goto
The polyaniline made using this method had the same crystallinity and electrical characteristics as if it had been made using traditional techniques, according to extensive experimental characterizations.
“A particularly exciting result is the ease of preparing industrially useful polymer alloys, such as blends with polystyrene or cellulose derivatives,” says Professor Goto. “Electrically conductive paint, advanced rubber blends, and other materials are now straightforward to prepare, which we expect will facilitate product development in diverse fields.”
What is it about the added iodine that facilitates polyaniline production?
Iodine, according to the researchers, is an electron-acceptor dopant that makes it easier to produce localized polarons, which are essential for the polymerization follows by radical chain reactions.
This study’s findings will make polyaniline more compatible with inkjet printing and other practical processing techniques, which will make it easier to produce printed circuit boards and other typical modern electronics components.
Many common and cutting-edge technologies will be simpler to produce and more affordable if we concentrate on the fairly abstract problem of solvent compatibility. This work was supported by the Japan Society for the Promotion of Science (JSPS, Grants-in-Aid for Scientific Research (KAKENHI).
