New lightweight materials offer many uses for plastic waste, say researchers

By Yiming Woo

SINGAPORE (Reuters) – Singaporean researchers are seeking a patent for a new sound-absorbing, heat-resistant material made from recycled plastic bottles that could help reduce plastic waste dumped in the oceans and clog landfills.

The National University of Singapore team reported finding a way to convert polyethylene terephthalate (PET) bottles into aerogels with many potential uses – from insulation and fire safety to cleanup of oil spills .

"Plastic waste is one of the most difficult wastes to recycle," Hai Minh Duong, an associate professor in the university's mechanical engineering department, told Reuters Television.

The team was looking for new engineering applications to help reduce the global scourge of plastic waste, he said.

According to the United Nations Environment Program, about eight million tons of plastic are dumped into the oceans each year, killing marine life and entering the human food chain.

According to a study conducted in 2015, five Asian countries – China, Indonesia, the Philippines, Vietnam and Thailand – accounted for up to 60% of plastic waste dumped in the oceans.

PET aerogels made from plastic bottle waste are flexible, durable, lightweight and easy to handle, said the team in a statement released this month.

The team indicated that recycled bottles can produce an A4 sized airgel sheet and that the material can be customized for various uses by adding surface treatments to improve its absorbency and insulation.

For example, a sheet coated with flame retardant chemicals could withstand temperatures of up to 620 degrees Celsius. It's seven times more than the usual thermal liner of a firefighter's coat and only 10% of the weight.

Versions of the material can also be used for thermal and sound insulation in buildings, cleaning oil spills and masks to absorb carbon monoxide.

The team published its research in the scientific journal Colloids and Surfaces A in August.

It filed a patent in March and is looking for partners for mass production of airgel. The cost of making a 1 meter by 1 meter sheet could be less than 10 Singapore dollars ($ 7.30), said Duong.

As countries struggle to cope with the growing accumulation of plastic and other wastes, Duong said their invention showed that engineering and technology could offer solutions.

"In the future, my dream is that (…) there will be no waste to recycle," he said.

($ 1 = 1.3709 Singapore dollar)

(Yiming Woo Report, edited by Darren Schuettler)