Introducing Students to Feedstock Recycling of End-of-Life Silicones via a Low-Temperature, Iron-Catalyzed Depolymerization Process

Autor/inn/en	Do¨hlert, Peter; Weidauer, Maik; Peifer, Raphael; Kohl, Stephan; Enthaler, Stephan
Titel	Introducing Students to Feedstock Recycling of End-of-Life Silicones via a Low-Temperature, Iron-Catalyzed Depolymerization Process
Quelle	In: Journal of Chemical Education, 92 (2015) 4, S.617-624 (5 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0021-9584
DOI	10.1021/ed5007579
Schlagwörter	Recycling; Synthesis; Plastics; Inorganic Chemistry; Undergraduate Students; Sustainable Development; Teaching Methods; Educational Practices; Science Experiments; Scientific Concepts; Scientific Methodology; Environmental Education + Suchen Sie Ihr Suchwort? Plastisches Material; Anorganische Chemie; Nachhaltige Entwicklung; Teaching method; Lehrmethode; Unterrichtsmethode; Bildungspraxis; Umweltbildung; Umwelterziehung; Umweltpädagogik
Abstract	The straightforward large-scale synthesis and the ability to adjust the properties of polymers make polymers very attractive materials. Polymers have been used in numerous applications and an increased demand is foreseeable. However, a serious issue is the accumulation of enormous amounts of end-of-life polymers, which are currently recycled by thermal degradation, undergo downcycling, or buried in landfills. In contrast, only a minor fraction of polymers is recycled by selective depolymerization processes to produce low molecular weight chemicals that can be polymerized to new polymers. Polysiloxanes (silicones) are widely used polymers, and recycling is challenging due to their intrinsic properties. A few high temperature or less environmentally friendly protocols have been reported for recycling silicones. To circumvent these problems, a lowtemperature process was developed for the depolymerization of polysiloxanes using catalytic amounts of cheap, iron salts as a precatalyst and benzoyl fluoride as a depolymerization reagent. Low molecular weight products (difluorodimethylsilane and 1,3-difluoro- 1,1,3,3-tetramethyldisiloxane) are used for the synthesis of new polysiloxanes; hence, overall a recycling process is feasible. This inorganic chemistry experiment introduces second-year undergraduate students to the concept of feedstock recycling via depolymerization/polymerization processes and exemplifies modern advances in sustainable chemistry. (As Provided).
Anmerkungen	Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01