MIT engineers design recyclable elastic yarn
A team of research scientists at MIT’s Department of Mechanical Engineering have been working on a modified polyethylene yarn that can be engineered to be elastic. The team, led by Svetlana Boriskina, began investigating the textile properties of polyethylene in 2021, focusing first on its moisture wicking, stain-resisting and cooling properties.
In a new study, the group has been able to tailor a polyethylene yarn to mimic the strength and elongation of spandex, as well as demonstrate the yarn’s recyclability. “The chemical structure of polyethylene is like Christmas garland — a backbone of carbon, carbon, carbon, and also these dangling ‘decorations’ of hydrogen atoms or short branches with the same structure as a backbone,” said Ms Boriskina. “How these chains are arranged can change the properties of the whole structure.”
They devised a bicomponent yarn that has a stretchy core made from one type of polyethylene-based resin. A second, stiffer resin makes up the yarn’s sheath, a construction that replicates that of corespun yarns with an elastane core.
The researchers have also demonstrated that the dual polyethylene can be spun into yarn, melted, and respun into new yarn. After 10 cycles, they found that the yarn did not lose any strength or flexibility.
Ms Boriskina and her colleagues published the details of their research in the journal ACS Materials Letters.
Photo Credit: Felice Frankel
