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Researchers report a simple method to convert food waste into cellulose-based plastics of varying thermal and mechanical properties (Macromolecules 2014, DOI: 10.1021/ma5008557).
Most synthetic plastics have environmental concerns: They’re petroleum-based; they can’t biodegrade; or they potentially contain toxic compounds such as phthalates. Ilker S. Bayer, Athanassia Athanassiou, and their colleagues at the Italian Institute of Technology have sought ways to make plastics from biomass so that the materials are renewable, biodegradable, and possibly less toxic. One potential feedstock is cellulose, which, as a component of plant cell walls, is nature’s most abundant renewable polymer.
In their new plastic-making method, the researchers turned to a technique that’s normally used to break down cellulose into simpler sugars for biofuel production: soaking the material in acid. Because the researchers only wanted to break apart the cellulose’s crystalline structure—and not convert it into simple sugars—the team used trifluoroacetic acid (TFA), which isn’t as strong as acids used in biofuel applications.
The team used TFA to soak inedible waste from four food crops: spinach, rice, cocoa beans, and parsley. After several days of soaking, the researchers removed the volatile acid, yielding plastic coatings and films with a variety of mechanical properties. These materials have tensile strengths similar to synthetic polymers such as polyethylene terephthalate and polyethylene, the researchers say. The plant-waste plastics start to thermally degrade at temperatures between 150 and 300 ºC, which is similar to the range for synthetic polymers.
參考譯文：
農產品加工過程中會產生大量不適合食用的廢料，例如米糠、果殼、綠葉類蔬菜難以食用的莖等等。這些廢料的主要成分是纖維素，這是一種有著良好機械性能的天然高分子，在許多場合可以代替人工合成的塑料。但是，植物中的纖維素通常以晶體的形式存在，加工比較困難。
來自意大利的研究人員近日發現，只要將這些廢料浸泡在一種常見的有機酸——三氟乙酸中，廢料中的纖維素的晶體形態就會逐漸被破壞，纖維素得以溶解在三氟乙酸中，便于進一步的加工。利用這種方法，研究人員成功將多種農產品加工過程中產生的廢料轉化為塑料，其機械強度、熱穩定性等性能均可以媲美常見的合成塑料，而且廢棄后可以在微生物的作用下逐漸降解。這項研究提供了以可再生的生物資源為原料生產塑料的一種新方法，有助于減輕塑料制品的生產對于化石能源的依賴以及對環境的破壞。
原始來源：http://cen.acs.org/articles/92/web/2014/07/Simple-Acid-Soak-Turns-Food.html
Most synthetic plastics have environmental concerns: They’re petroleum-based; they can’t biodegrade; or they potentially contain toxic compounds such as phthalates. Ilker S. Bayer, Athanassia Athanassiou, and their colleagues at the Italian Institute of Technology have sought ways to make plastics from biomass so that the materials are renewable, biodegradable, and possibly less toxic. One potential feedstock is cellulose, which, as a component of plant cell walls, is nature’s most abundant renewable polymer.
In their new plastic-making method, the researchers turned to a technique that’s normally used to break down cellulose into simpler sugars for biofuel production: soaking the material in acid. Because the researchers only wanted to break apart the cellulose’s crystalline structure—and not convert it into simple sugars—the team used trifluoroacetic acid (TFA), which isn’t as strong as acids used in biofuel applications.
The team used TFA to soak inedible waste from four food crops: spinach, rice, cocoa beans, and parsley. After several days of soaking, the researchers removed the volatile acid, yielding plastic coatings and films with a variety of mechanical properties. These materials have tensile strengths similar to synthetic polymers such as polyethylene terephthalate and polyethylene, the researchers say. The plant-waste plastics start to thermally degrade at temperatures between 150 and 300 ºC, which is similar to the range for synthetic polymers.
參考譯文：
農產品加工過程中會產生大量不適合食用的廢料，例如米糠、果殼、綠葉類蔬菜難以食用的莖等等。這些廢料的主要成分是纖維素，這是一種有著良好機械性能的天然高分子，在許多場合可以代替人工合成的塑料。但是，植物中的纖維素通常以晶體的形式存在，加工比較困難。
來自意大利的研究人員近日發現，只要將這些廢料浸泡在一種常見的有機酸——三氟乙酸中，廢料中的纖維素的晶體形態就會逐漸被破壞，纖維素得以溶解在三氟乙酸中，便于進一步的加工。利用這種方法，研究人員成功將多種農產品加工過程中產生的廢料轉化為塑料，其機械強度、熱穩定性等性能均可以媲美常見的合成塑料，而且廢棄后可以在微生物的作用下逐漸降解。這項研究提供了以可再生的生物資源為原料生產塑料的一種新方法，有助于減輕塑料制品的生產對于化石能源的依賴以及對環境的破壞。
原始來源：http://cen.acs.org/articles/92/web/2014/07/Simple-Acid-Soak-Turns-Food.html
