A minuscule addition of a so-called wonder material can notably strengthen plastic bottles while making them lighter, a possible path to improved sustainability, tests for Toronto-based HydroGraph Clean Power Inc. (HG-CN) have found.

By adding 0.006 per cent, by weight, of a material called graphene into an equal blend of recycled and virgin plastics, the robustness of the bottles was improved, the amount of water that can seep through the plastic minimized, and the weight of a bottle potentially shaved by up to one-fifth.

The findings in research conducted at the Graphene Engineering Innovation Centre (GEIC) at the University of Manchester indicate the potential to cut millions of tonnes of carbon dioxide from production of plastic bottles, and may even boost recyclability, Kjirstin Breure, CEO of HydroGraph, told Sustainable Biz Canada in an interview.

Breure said the graphene addition is so small it will have minimal impact on the price of the plastic.

“The customer doesn’t feel that economically. There’s so many clear benefits that for us, looking at this data, we feel that this really is a slam dunk in the industry,” she said.

Graphene, which was discovered at the University of Manchester, is 200 times stronger than steel and is 1,000 times more conductive than copper, according to HydroGraph. Its unique properties have caught the attention of researchers for its versatility. The material can serve as a concrete additive, and can improve batteries and solar panels.

Testing its graphene where it was discovered

HydroGraph is behind an energy efficient, greenhouse-gas-free technology called the Hyperion detonation process that produces highly pure graphene powder.

To understand how graphene could be used in the plastics industry, HydroGraph sent its material to scientists at the University of Manchester in 2023. The researchers mixed graphene into a blend of virgin and recycled polyethylene terephthalate (PET), which was blown into water bottles by a third-party company.

PET is a commonly used plastic for transparent beverage bottles and food-grade film. Over 50 million tons are made per year, according to research by the National Library of Medicine, primarily for single-use packaging. HydroGraph took an interest in PET because the company is searching for materials that can go to market quickly and have low barriers of entry, Breure said.

The results showed enhanced strength and reduced permeability, which has implications for the plastics industry.

A 23-per-cent improvement in top-load strength, an 83 per cent decrease in the water vapour transmission rate, and a potential 20 per cent weight reduction were observed.

Thinner, better plastics

“That means for the same traits we’re looking at, we’re using less plastic, so by making that plastic wall thinner, we’re reducing the amount of PET that’s needed to have the type of bottle we’re looking for,” Breure explained.

A higher top-load strength means more bottles can be stacked to increase shipping rates, raising delivery volume while reducing transportation costs from the decreased weight per bottle.

If the company’s graphene powder reaches full commercialization, it could cut PET production by five million tonnes per year, with an associated offsetting of eight million tonnes of carbon dioxide, HydroGraph says.

Additionally, the lower water vapour transmission rate (indicating how much water can pass through the plastic) means improved shelf life and less contaminants from the PET will leach into the water, Breure added.

The tests at GEIC have not indicated specialized infrastructure will be required if the graphene-enhanced plastic joins the recycling stream. Rather, the preliminary results hint at the plastics becoming more recyclable, Breure said (though the results need to be repeated before there is more confidence in that assertion).

Typically, recycling PET means the quality of the plastic is degraded, limiting the amount of times it can be reused. But adding graphene has suggested a boost to mechanical strength, regardless of the blend of plastics, Breure said.

If PETs are more recyclable, it would be a boon to the environment as it means less plastics need to be made to satisfy demand.

Commercializing graphene for PET

HydroGraph is aiming its graphene powder toward customers such as water bottle producers that would connect the company to their supply chains such as a polymer maker.

The company has submitted its product for approval by the U.S. Environmental Protection Agency and Food and Drug Administration (FDA). Breure said the data from the FDA tests, which are about halfway through, are encouraging.

Breure, who has been with HydroGraph for almost five years, became CEO earlier this month after being named interim chief executive in March. She has risen the ranks from president and chief operating officer.

The company’s strategy has shifted from business development to application development. Rather than start from a sales role with unclear graphene customers, HydroGraph is extensively exploring business cases so it will have buyers, she said.

Occupying her time as of late is expediting commercialization, looking beyond PET bottles and food-grade packaging into the automotive and aerospace industries, UV protection coatings, batteries, biosensors and concrete. Partnerships with Volfpack Energy and NEI Corporation were announced earlier this month as collaborations on battery materials development.

“The future’s quite limitless” for graphene, Breure said.

HydroGraph currently has the capacity to produce 10 tonnes of graphene per year at its facility in Kansas. To increase production, the company has plans for a larger facility that will likely be in Texas.

More tests will be conducted to get a better idea of how graphene affects the recycling stream, Breure said. Graphene could be “absolutely huge” for sustainability, so a priority for HydroGraph is understanding if the result that found improved recyclability is a one-time event or replicable.