Editors: | F. Kongoli, F. Marquis, N. Chikhradze, T. Prikhna, M. De Campos, S. Lewis, S. Miller, S. Thomas. |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2022 |
Pages: | 290 pages |
ISBN: | 978-1-989820-68-1(CD) |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Biomass is a sustainable and renewable source of valuable monomers. However, the number of monomers that can be obtained from biomass processing is rather limited. In addition, the recycling of used polymeric materials is still challenging.
Here, a sustainable strategy of bio-based polymers recycling was described. First, a series of vinyl ethers was obtained from selected terpenols according to the well-established procedure for vinylation with calcium carbide [1-4]. Further, from the obtained monomers, the corresponding polymers were synthesized by standard procedures. Polymers possessed a certain plasticity and thermal stability, which made it possible to melt them repeatedly without decomposition and changes in properties. After cooling, the polymers became solid again and retained their shape.
The obtained polymeric materials were heated under inert atmosphere at different temperatures (pyrolysis) [5]. It was found that the pyrolysis products under certain conditions were only the starting alcohols (terpenols) and the corresponding aldehydes or ketones. It should be noted that all pyrolysis products are natural compounds.
After pyrolysis, the resulting liquid mixtures were collected and reduced with sodium borohydride. Thus, the corresponding ketones and aldehydes were again converted into the starting alcohols. The yields of these processes were quantitative. Thus, the mixture after the pyrolysis and reduction consisted the starting alcohol. The alcohol was again vinylated with calcium carbide, and then vinyl ethers and corresponding polymers were again obtained. The properties of the re-obtained polymers were found to be the same as initially. Thus, the resulting polymer materials can be recycled many times after the end of life.
In presentation, the synthetic and analytical data will be presented (TGA, DSC, NMR, etc.), characterizing the properties of the obtained compounds and polymers.
This work was supported by the Russian Science Foundation (21-73-20003).