99% of ‘immortal’ silicone recovered from waste at just 176°F with new chemical method

Technische Universität Berlin has developed a new catalytic process to fully break down silicone waste. Common items like the silicone spatula in your mixing bowl, the leak-proof seal in your travel mug, and the soft pacifier that keeps a toddler quiet all share a hidden downside. All are immortal. Silicones resist heat, water, and chemical breakdown. Hence, throwing the waste away usually means sending it to a landfill or an incinerator. Until now, a closed-loop recycling has been a tough task, chemically. TU Berlin says they have found a way forward after years of research. Led by Professor Dr. Martin Oestreich, the team developed a catalytic process that breaks down silicon-oxygen polymers back into their original, high-value building block: dimethyldichlorosilane. The study details a strategy that gives up to a 99% recovery rate from regular items like muffin pans and baby bottles. “Our success is proof that basic research can eventually pay off in very specific applications that no one had previously thought of,” said Oestreich. “We’ve been conducting research on silylium ions for 15 years, and it’s only in the last five years or so that we have suddenly identified the recycling of silicones as a key application for this research.” Breaking the bad silicone The discovery simply solves a tough chemical problem. To make fresh silicone from scratch, manufacturers first extract raw silicon from quartz sand inside electric arc furnaces fired at extreme temperatures. It is a massive, energy-intensive undertaking. Once formed, the resulting silicon-oxygen bonds behave like molecular superglue. Breaking them requires immense energy or unprecedented catalytic precision. Oestreich’s team spent 15 years studying the silylium ions (positively charged silicon ions) before realizing the hidden potential for waste management. As per the study paper, a new silylium-ion-initiated depolymerization strategy has been developed to enable the sustainable circular recycling of chemically inert silicone (siloxane) materials. When paired with triphosgene — a manageable solid reagent —the silylium ion strips away a chloride ion to generate a hyper-reactive species known as a chlorocarbonyl cation (COCl+). This molecular scissors snip the silicon-oxygen chain. As the bonds snap apart, the oxygen escapes cleanly into the air as carbon dioxide gas (CO2), preventing the reaction from reversing. The entire sequence runs at a gentle 80°C, requiring negligible energy compared to primary production. Growing silicone waste crisis Testing on items like cupcake pans and lids demonstrated promise. Under moderate conditions at 80°C (176°F), the low-energy process recovered up to 99 percent of dimethyldichlorosilane from individual items within 24 hours. Even when applied to a mixed batch of diverse silicone waste, the method maintained a 86 percent recovery rate. The market for silicone products is continuously growing. It was around USD 19.55 billion in 2025 and is expected to reach USD 37.70 billion or more by 2035. Usual recycling methods use mechanical processing or chemical breakdown into small, ring-shaped siloxanes. Although these recycled compounds can form new silicone products, the resulting materials are typically lower quality than virgin silicone. The newly detailed process makes recycling silicone waste possible, turning unrecyclable plastic-like materials back into useful industrial ingredients. With a patent already filed, the researchers are turning their attention toward commercial scaling. And are currently hunting for non-toxic phosgene alternatives and designing purification stages to strip out trace contaminants. The study findings were published in the journal Nature on October 28. Get the latest in engineering, tech, space & science - delivered daily to your inbox.Mrigakshi is a science journalist who enjoys writing about space exploration, biology, and technological innovations. Her work has been featured in well-known publications including Nature India, Supercluster, The Weather Channel and Astronomy magazine. If you have pitches in mind, please do not hesitate to email her.