Scientists devise new process that turns old PLA plastic into better 3D printing resin
“[Polylactic acid] is biodegradable and compostable, but once you study it, it can take up to as long to decompose in landfills,” said Yu-Chung Chang, a postdoctoral researcher and co-corresponding author of the paper. 100 years. In reality, it still creates a lot of pollution. We want to make sure that when we do start producing PLA on a million-ton scale, we’ll know what to do with it.”
To do this, Chang and his colleagues developed a process in which an inexpensive chemical called aminoethanol is used to break down the long-chain molecules that make up polylactic acid. These chains are broken down into simple monomers, the basic building blocks of plastics. The process takes about two days and can be done at mild temperatures.
Next, the monomers are recombined to form light-curable resins, similar to those already used in some 3D printers. In fact, when used for 3D printing of test objects, the PLA-derived resin was found to exhibit mechanical and thermal qualities equal to or better than those of existing commercial resins.
“We’ve found a way to instantly turn it into something stronger and better, and we hope this will inspire people to recycle this stuff instead of just throwing it away. We’re making stronger materials straight from the trash. We believe this could be a great opportunity,” Chang said.
The scientists now hope to apply the technique to another commonly used plastic, polyethylene terephthalate (PET).