Novel Polymers With Extreme Stretching, Vibration Suppression And Self-Healing

Novel polymers with extreme stretching, vibration suppression and self-healing

05-Jul-19

An Oak Ridge National Laboratory led team has developed super-stretchy polymers with amazing self-healing abilities that could lead to longer-lasting consumer products. The polymers are among the world’s stretchiest and can elongate about 1,000 - 5,600% before breaking. After breaking, they can be healed with complete restoration of elasticity by merely touching adjacent pieces. When damaged, the rubbery polymers (elastomers) completely heal in 120 minutes at room temperature. They heal in 20 minutes at slightly higher temperatures. Healing fully restores the material and lets it go back to work. After a cut, the super-stretchy material heals itself and resumes working (for example, separating gases). This self-healing feature could lead to longer lasting, better performing films and other products. The novel elastomers illustrate a synthetic approach to promising materials for use as films, membranes, coatings, and other devices.

By tailoring the properties of segments and how they link to the polymer, the scientists tuned tensile strength, toughness and elastic recovery. They used stretchy polymeric strips to create a permeable membrane that selectively separated two gases. After that membrane broke, it self-healed to once again separate the gases. Tailoring the degree of hydrogen bonding was the key to self-healing and could be exploited to make other self-healing materials. “These novel materials provide an attractive platform for fabrication of functional films, membranes, coatings and devices with prolonged lifetimes,” said ORNL’s Tomonori Saito. Novel polymeric elastomers are an attractive platform for creating materials capable of extreme stretching, absorbing energy during vibration, and repairing damage from cuts and tears. The elastomers also exhibited excellent acoustic and vibration damping properties and quickly recovered from being stretched. After mechanical damage, elastomers could be healed - with complete restoration of mechanical performance in 120 minutes at room temperature. Healing took less time at increased temperature. Healed elastomers recovered their permeability and selectivity in separation of gases. The super-stretchy materials could be useful, for example, in self-healable functional surfaces, membranes, and mechanical energy absorbers (such as vibration dampers).