Professor Wang Shiqing from the College of Polymer Science and Polymer Engineering of the University of Akron has made important progress in sustainable bioplastics.
Professor Wang Shiqing and his team have been committed to researching the transformation of brittle polymers into tough and flexible polymers. The team recently developed a new type of polylactic acid (PLA) cup. This cup has good transparency, good toughness, and does not shrink when filled with boiling water.
"Now, plastics have become an important part of our daily lives. Since most plastics cannot be recycled, they will accumulate in landfills," said Professor Wang Shiqing. "But some promising biodegradable materials, such as PLA Because of its fragility, it is usually difficult to replace high-molecular-weight polymers using fossil fuels as raw materials, but the newly developed PLA cup overcomes this difficulty.
Dr. Ramani Narayan, a professor in the Department of Chemical Engineering and Materials Science at Michigan State University and a famous bioplastics scientist, commented on the latest results of Professor Wang Shiqing’s team: “PLA is the world’s most important 100% bio-based and fully compostable polymer, but it has more Poor toughness and low heat distortion temperature, it will soften at 140°F (60°C) and be structurally damaged, which makes it unusable in many hot food packaging and disposable containers. But Professor Wang's research is here It still maintains stable performance in temperature. This achievement may become an important breakthrough in the PLA market."
To explain how this PLA cup can improve flexibility and heat resistance, Professor Wang Shiqing used cooked pasta as an analogy. If the molten PLA is magnified one million times, each chain molecule looks like a pile of spaghetti, several meters in length. To make PLA tough, the key is not to destroy the interwoven structure of "spaghetti" during the crystallization process.
Professor Wang Shiqing calls this interwoven structure a "chain network." During operation, the experimental team needed to limit the PLA crystals to the nanometer level while keeping this chain-like network from being destroyed. This structure can ensure that the PLA beverage cup is transparent, strong and heat-resistant in physical properties.
This transparent cup can hold hot tea and coffee, and can replace most plastic beverage cups on the market. Professor Wang Shiqing said: "Our new research results may bring about a double growth of the PLA packaging market."