Depolymerization of polylactic acid
US8895778B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 2012 |
| Grant date | Nov 25, 2014 |
| Priority date | — |
| Expiry date | Jun 10, 2032 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/412
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention provides energy efficient depolymerization of polyesters such as post-consumer polylactic acid. Ultrasonic induced implosions can be used to facilitate the depolymerization. The expanding market of polylactic acid-based plastic products, such as water bottles and packaging materials, has raised concerns of contaminating the recycling stream, which is largely filled with petroleum-based plastics. Thus the development of an energy efficient and economically viable PLA recycling process is urgently needed. Post consumer PLA was exposed to methanol as the suspension media in the presence of organic or ionic salts of alkali metals such a potassium carbonate and sodium hydroxide as depolymerization catalysts to provide high quality lactic acid monomers in high yield.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.