Jeonju, South Korea – The growing interest in biobased polyols for polyurethanes has led to a need to overcome the challenges posed by differences in chemical structure from fossil-based polyols. Two such challenges, low self-healing and poor conductivity, have been addressed by scientists at Jeonbuk National University, who have created biobased PU composites with potential in flexible supercapacitors.
The electrically self-healing biopolymer composites were created by incorporating carbon nanotube networks into the castor oil-based PU via a curing process. They claim the new materials have better mechanical, electrical and self-healing capabilities than other self-healing biobased materials, being able to restore both mechanical properties and electrical performance after severe mechanical damage.
The composite functioned as a conductive substrate in flexible solid-state supercapacitor devices. These devices had a self-healing efficiency above 90% even after being subjected to seven cycles of cutting and healing, and remained almost unchanged after being bent at a 180° angle.
The self-healing ability was attributed to synergistic interactions of the dynamic exchange reactions of disulfide bonds and dense hydrogen bonds within the PU matrix. These, they said, provide a reversible dynamic polymer network, and lay the groundwork for the design of sustainable polymer composites in the future.
The work has been published in the Journal of Materials Science & Technology.
