This presentation will showcase our recent work on the development of circular methodologies for siloxane-based elastomers and resins. We have developed an efficient methodology to depolymerize polysiloxanes of various forms and cross-link densities to cyclic siloxanes of D4, D5, and D6 and then demonstrate their repolymerization back to polysiloxane structures. The depolymerization processes are conducted using a cocktail of fluoride ions from tetrabutyl ammonium fluoride or from photoreleasable flourides from phenacyl photocages in THF and other intermediate high swell solvents. The reactions are highly efficient with conversion to cyclomers taking place in as little as 30 min through an equilibration process, with quenching by CaCl&lt;font size="1"&gt;2&lt;font size="1"&gt; &lt;/font&gt;&lt;/font&gt;to remove active fluoride ions and lock the cyclic structures. The conversion to cyclomers are verified by 29Si NMR and GCMS spectroscopic techniques. Traditional methods such as triflic acid initiated polymerization have shown effective repolymerization to polysilxanes.

Full circle polysiloxane depolymerization to cyclic monomers and back again

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.