New approach to silicone waste recycling closes the loop

(Press-News.org)  

A new low-energy chemical recycling method using boron and gallium can convert common silicone waste into useful chlorosilanes with high efficiency and yield. The method offers a promising new chemical pathway toward circularity in silicone materials, addressing both resource sustainability and emissions reductions in the industry. Prized for their durability, heat and chemical resistance, and low toxicity, silicone polymers are found in countless everyday products, ranging from medical devices to car parts. Each year, millions of tons of silicone are produced globally. Producing silicones is highly energy-intensive, with over 70% of their carbon footprint stemming from the extraction and subsequent chemical processing of component materials. Thus, improving silicone recycling is critical – not only to conserve valuable raw materials like quartz but also to significantly reduce energy use and environmental waste. However, while recycling of carbon-based polymers has advanced, recycling silicone polymers remains challenging due to their complex chemical makeup and robust material properties. Here, Nam Duc Vu and colleagues present a versatile chemical recycling strategy to break down a wide range of silicone-based materials, including those commonly used in consumer and industrial products. Vu et al.’s approach uses a gallium catalyst and boron trichloride reagent to depolymerize silicone, at a mild 40° Celsius, into quantitative amounts (~97% yields) of high-purty chlorinated silane monomers, which are key building blocks in silicone manufacturing. According to the authors, the method is scalable and closes the loop on silicone materials by enabling re-synthesis of fresh silicones from waste. In a related Perspective, Koushik Ghosh discusses the study in greater detail.

 

For reporters interested in research integrity issues, Perspective author Koushik Ghosh notes, “recent efforts in my field have made strides toward addressing science integrity-related issues, particularly through initiatives aimed at improving transparency, reproducibility, and ethical research practices. However, one area I believe requires greater emphasis is prioritizing quality over quantity in scientific output. The current landscape often incentivizes the production of numerous publications, sometimes at the expense of originality and rigor. I would like to see a stronger focus on fostering truly innovative research, with an honest acknowledgment of the value of "failure experiments."

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