Researchers in the US have developed an environmentally friendly, biodegradable material from soy flour resin and flax yarn. It is made from plant fibres and resins - renewable sources - making the composite material a greener alternative to petroleum-derived materials. 

This composite has good physical and mechanical properties compared to similar materials made from renewable resources - the yarn reinforces the resin, which is also cross-linked to improve its strength. It was developed by Anil Netravali and colleagues at Cornell University and the Georgia Institute of Technology. 

The resin-yarn material is strong and durable enough for low-load indoor applications. Resin and yarn are expected to degrade easily at the end of the composite material's life.   

Minimising waste by composting is a considerable benefit of this material over traditional plastics, whose very strength and stability make them difficult to degrade and adds large volumes of waste to landfill sites. 

Flax yarn's low density makes it an attractive fibre-reinforcement material for applications where weight is a consideration, says Ian Hamerton at the University of Surrey. However, natural fibres might limit these materials' widespread use.   

Reliable and predictable mechanical performance is also critical to structural applications and the quality of the raw materials needs to be consistent. Natural fibres are not uniform and those from a single species of plant change with the climate and growing season. 'Processing raw materials with consistent dimensions and properties is probably the main challenge,' said Hamerton. 

Vikki Allen