{"id":669689,"date":"2026-10-30T08:40:21","date_gmt":"2026-10-30T08:40:21","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/669689\/"},"modified":"2026-10-30T08:40:21","modified_gmt":"2026-10-30T08:40:21","slug":"breakthrough-in-silicone-recycling","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/669689\/","title":{"rendered":"Breakthrough in Silicone Recycling"},"content":{"rendered":"

Silicones are widely used in industry, medicine, and everyday products due to their exceptional thermal and chemical stability. However, precisely because of these properties, recycling<\/a> silicones has been considered extremely problematic until now. Researchers at the Institute of Chemistry at TU Berlin have now succeeded in breaking down the polymer chains of silicone molecules into their basic building blocks. The resulting dimethyldichlorosilane can then be reused as a starting material for the production of new silicone compounds.<\/p>\n

The process has already been submitted for a patent and is based on a complex interplay of several chemical reaction cycles. The research team led by Prof. Dr. Martin Oestreich has successfully tested it on various used silicone products from everyday life. Due to its great significance for green chemistry and the circular economy, the paper was selected by the renowned journal *Nature* for \u201cFast Track\u201d online publication. Martin Oestreich is also a member of the UniSysCat Cluster of Excellence in Catalysis at TU Berlin.<\/p>\n

The market for silicone products is enormous: it was worth more than 21 billion euros in 2025 and is estimated by analysts to exceed 33 billion euros by 2033. In addition to their thermal and chemical stability, silicones are also characterized by outstanding mechanical properties. Furthermore, the material reliably repels water while remaining permeable to oxygen. Silicones are found in numerous everyday products\u2014from baking pans and baby bottle nipples to seals and medical tubing. \u201cDue to its robust properties, recycling used silicone is very difficult,\u201d says Prof. Dr. Martin Oestreich, Einstein Professor, head of the \u201cOrganic Chemistry\/Synthesis and Catalysis\u201d department, and a member of the UniSysCat Cluster of Excellence at TU Berlin. \u201cUntil now, waste silicone has mostly been incinerated or landfilled. In recycling, the material is often mechanically processed or chemically broken down into smaller, ring-shaped siloxanes, from which silicones can be produced again. However, these new silicones are usually of lower quality than the original ones.\u201d<\/p>\n

Silicone production is extremely energy-intensive\u2014making recycling highly beneficial<\/p>\n

Complete recycling of silicones would be desirable, on the one hand, because there is growing evidence that silicones sent to landfills can be harmful to the environment and human health. On the other hand, the production of silicones requires enormous amounts of energy. For example, the elemental silicon required for this must be extracted from quartz sand at temperatures of 2,000 degrees Celsius. Using this silicon, dimethyldichlorosilane\u2014the basic building block of silicone chemistry\u2014is then produced via a special process. \u201cThis molecule can be strung together into long chains, with the chlorine it contains being replaced by oxygen,\u201d explains Oestreich. Similar to carbon chemistry, it is not carbon atoms but bonds between silicon (Si) and oxygen (O) that form the \u201cbackbone\u201d of the resulting polymers (Si\u2013O\u2013Si\u2013O\u2013Si). To tailor the properties of various silicones, one can vary the chain length and attach various other molecules to the sides of the chains.<\/p>\n

The key to breaking the silicone chains: the silylium ion as a catalyst and phosgene<\/p>\n

An ideal recycling process would include the ability to produce new silicones with different properties from end-of-life silicones of a particular type. \u201cTo achieve this, the base molecule dimethyldichlorosilane must absolutely be produced at the end of the recycling process,\u201d says Martin Oestreich. To do this, the Si\u2013O\u2013Si chains of the silicones must be completely broken down. \u201cBreaking the silicon-oxygen bonds is extremely difficult. That\u2019s precisely why silicone is such a stable material.\u201d The researchers have now succeeded in doing this primarily through the use of two molecules: a \u201csilylium ion\u201d as a catalyst and the gas phosgene. A silylium ion is the term used to describe chemical compounds that contain a positively charged silicon atom. In a complex interplay of several reaction cycles, the silylium ion removes a chloride ion (Cl\u207b) from phosgene (COCl\u2082). What remains is the compound COCl\u207a. \u201cThis molecule then has the chemical power to break a silicon-oxygen bond,\u201d says Oestreich. Another advantage of the process is that the oxygen from the broken Si\u2013O\u2013Si chains immediately escapes as carbon dioxide (CO\u2082). \u201cThe oxygen is thus bound in a stable compound and immediately removed as a gas. This means it is no longer available for other reactions.\u201d<\/p>\n

Phosgene is toxic but is used industrially in large quantities<\/p>\n

Phosgene is a toxic gas\u2014which is why the researchers did not use it directly; instead, for safety reasons, they used the more manageable solid triphosgene, which only releases phosgene during the reaction cycle. This conversion is also catalyzed by the silylium ion, which thus performs a dual function. \u201cHowever, the use of phosgene is by no means uncommon in the chemical industry. For example, important starting compounds for polyurethanes\u2014which are used to make foams and insulation materials\u2014are produced using phosgene,\u201d explains Martin Oestreich. Nevertheless, his research group is already working on finding alternatives to phosgene. In addition, they aim to develop methods to purify dimethyldichlorosilane recovered during the recycling process of even the smallest traces of phosgene.<\/p>\n

Tests with Everyday Products: Very High Recycling Yield<\/p>\n

With temperatures of 80 degrees, the reaction conditions are moderate, allowing the process to be carried out without significant energy consumption. The researchers have already tested it on silicone cupcake pans, baby bottle nipples, silicone lids, and other silicone products. The results were promising: For individual products, the yield of recovered dimethyldichlorosilane reached up to 99 percent after 24 hours. A mixture of various used silicone products yielded 86 percent.<\/p>\n

Basic research pays off \u2013 patent application filed<\/p>\n

\u201cOur success is proof that basic research can eventually pay off in very concrete applications that no one had thought of before,\u201d says Martin Oestreich. \u201cWe\u2019ve been researching silylium ions for 15 years, and it\u2019s only been about five years since we suddenly saw an important practical application for this research in the recycling of silicones.\u201d The process has already been submitted for patenting.<\/p>\n","protected":false},"excerpt":{"rendered":"Silicones are widely used in industry, medicine, and everyday products due to their exceptional thermal and chemical stability.…\n","protected":false},"author":2,"featured_media":669690,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[61,60,82],"class_list":["post-669689","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ie","tag-ireland","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/669689","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=669689"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/669689\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/669690"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=669689"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=669689"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=669689"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}