Cheaper bioplastics from waste oil

The trend towards seeing waste as an underutilised resource is benefiting the packaging sector, with University of Wolverhampton researchers finding a way to use waste oil from deep-fried food to create environmentally friendly plastic cheaply.

A research team from the School of Applied Sciences at the university has found that using waste cooking oil in the creation of bioplastics could reduce the cost of production while reducing environmental contamination caused by waste oil disposal.

Traditionally, the PHA (polyhydroxyalkanoate) family of polyesters is synthesised by a variety of bacteria, using glucose as a starting material. This produces non-toxic, biodegradable biopolymer used in a range of agricultural, marine and medical applications. However, producing bioplastics this way is expensive because glucose is used.

But the University of Wolverhampton researchers have found that using waste oil as a starting material reduces production costs.

“Our bioplastic-producing bacterium, Ralstonia eutropha H16, grew much better in oil over 48 hours and consequently produced three times more PHB than when it was grown in glucose,” said researcher Victor Irorere.

Poly 3-hydroxybutyrate (PHB) is the most commonly produced polymer in the PHA family.

“Electrospinning experiments, performed in collaboration with researchers from the University of Birmingham, showed that nanofibres of the plastic produced from oils were also less crystalline, which means the plastic is more suited to medical applications.”

Using glucose as a starting material has seriously hampered efforts to commercialise bioplastic production, said Dr Iza Radecka, who led the research. “Using waste cooking oil is a double benefit for the environment as it enables the production of bioplastics but also reduces environmental contamination caused by disposal of waste oil.”

The research group now aims to conduct experiments to enable the manufacture of bioplastics on an industrial level.