Articles & Issues
- Language
- English
- Conflict of Interest
- In relation to this article, we declare that there is no conflict of interest.
- Publication history
-
This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/bync/3.0) which permits
unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
All issues
Direct Conversion of Waste PET to Regenerated Plastics Using Flame Retardants as Depolymerization Catalysts
Abstract
Polyethylene terephthalate (PET) has been extensively used in the packaging industry, particularly for the production of
plastic bottles. PET wastes can be converted into monomeric and oligomeric substances through depolymerization and
purifi cation processes. Currently, the chemical recycling of waste plastics is one of the most viable environmental strategies,
and the direct repolymerization of depolymerized chemicals without any purifi cation is gaining signifi cant attention because
of its simple and cost-eff ective recycling characteristics. In this study, expandable graphite (EPG) and zeolites were used as
glycolysis catalysts for PET depolymerization, and then the reaction product was directly used to polymerize polyurethane
foams (PUFs). Both EPG and the zeolites could depolymerize PET, achieving PET conversion as high as 90% with bis(2-
hydroxyethyl terephthalate) yields of > 50%. PUFs were also eff ectively produced from both depolymerized batches, and
all PUF samples had a limiting oxygen index of > 31%, indicating high fl ame retardancy. Thus, EPG and zeolites can play
dual roles as glycolysis catalysts and fl ame retardants. Additionally, this study proposes an effi cient PET recycling route.
