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Akron University's latest progress in bio based plastics is likely to make significant progress in the sustainable development of plastics in the future.

In Dr. Wang's lab in the College of polymer science and polymer engineering, their whole team is studying how to transform brittle polymers into tough and flexible materials.

Their team recently developed a prototype polylactic acid (PLA) cup, which is transparent and tough, and full of boiling water without shrinkage and deformation.

Wang Shiqing

In 1982, he obtained a bachelor's degree in physics from Wuhan University, and was one of the first batch of university graduates. He spent the first nine months at the University of Rochester, then moved to the University of Chicago for a doctorate. In 1987, he obtained his Ph.D. in physics and worked with Karl freed to calculate the renormalization group of linear viscoelasticity of dilute polymer solutions. After two years of postdoctoral research with William Gelbart at UCLA, Wang joined the school of polymer science and engineering at Case Western Reserve University in the fall of 1989. He has been teaching in the Department of polymer science at Akron University since the fall of 2000.

Dr. Wang Shiqing pointed out: plastics have become an important part of our lives. Most of the plastics that can not be recycled will be piled up in landfills. Some promising biodegradable and degradable alternatives, such as PLA, are usually insufficient to replace fossil fuel based polymers such as pet. Because these degradable alternatives are generally fragile.

Dr. Ramani Narayan, a distinguished professor in the Department of chemical engineering and materials science at Michigan State University, said: Dr. Wang's research is likely to make a breakthrough in the PLA market.

He believes that PLA is 100percent of the world's bio based materials, and is a fully compostable polymer. But it has low toughness, heat resistance, at about 60 degrees Celsius, it will become soft and collapse in the structure. These properties make it impossible to use in many hot food packages and disposable containers.

So he thinks Dr. Wang's research is a disruptive technology, because Dr. Wang's prototype PLA cup is strong, transparent and can hold boiling water.
The standard PLA cup developed by Dr. Wang Shiqing, a professor of polymer science, is transparent and super tough, and does not shrink when filled with boiling water.

Dr. Wang has been teaching at Akron University for 20 years. He has been working hard to build a knowledge base to understand the relationship between processing, structure and properties of various plastics, and to use the latest knowledge to deal with the brittleness of PLA.

To explain the scientific basis of how his prototype PLA cup achieves ductility and heat resistance, Dr. Wang uses cooked spaghetti as an analogy. If the melting PLA is magnified a million times, each chain molecule looks like a few meters of spaghetti. For thermoplastics (including PLA), toughness is very important, that is, the crystallization process can not eliminate or destroy the entanglement of "spaghetti strand".

He called this interwoven structure "chain net". With this structure, anyone can take almost all the spaghetti out of the bowl with a pair of chopsticks. If operated correctly, this chain network ensures that the PLA beverage cup is still physically hard and does not crystallize. But such a cup will collapse when boiling water is poured in. "A cup made of ordinary crystalline polylactic acid can hold boiling water, but it's very brittle and opaque," Dr. Wang said

By studying the origin of the ductility of semi crystalline polymers, Wang's team found a way to limit the crystals in PLA to nano scale, while retaining the network to form transparent, tough and heat-resistant cups. This transparent cup can hold hot tea and coffee, and can replace most plastic beverage cups on the market.

"The results of our new research will eventually stimulate the PLA market to multiply," Wang said