POLYMER BRICKS MADE FROM WASTE BIND TOGETHER WITHOUT MORTAR

Making building materials is a messy business. Making the cement used in concrete accounts for as much as 8 percent of the world’s carbon dioxide emissions. 

Engineers have tried mixing wood waste, coal ash, and even ground-up tires into concrete to moderate its environmental impact.

At Australia’s Flinders University, researchers decided to do without concrete entirely.

Instead, they turned to a process they had developed previously to reclaim sulfur from industrial waste and make long-chain molecules from it that could capture waste heavy metals or be used as a fertilizer ingredient.

More recently, the developers mixed their sulfur polymers with canola oil and dicyclopentadiene (DCPD), a leftover from petroleum refining.

They heated the mixture, cured it, and molded it into blocks in a process requiring far less energy than making cement.

Perhaps even more impressive, the bricks stick to each other when sprayed with a nitrogen-based catalyst—no mortar required. After the bricks adhere to each other, any remaining catalyst evaporates.

In stress tests, the catalyst held the bricks together better than superglue.

In addition, the new bricks are more resistant to water, acid, and harsh weather than traditional bricks or concrete.

In another experiment, adding carbon fiber to the bricks made them 16 times strong than they were already, the engineers reported.

The developers are working with Clean Earth Technologies, a waste mitigation firm in Australia, to commercialize their invention.

TRENDPOST: The company will need time to structure a supply chain to gather the waste materials to make the bricks. Fortunately, the sulfur and DCPD can be picked up from oil refineries’ waste streams and canola oil is a common product.

The new brick-making process can turn refinery waste into a feedstock for new materials in another contribution to the circular economy.