DISINTEGRATING POLYSTYRENE

Foam polystyrene is a major environmental concern. It is used as a protective packaging for all sorts of products, but it is not biodegradable. Various manufacturers have experimented in making it more environmentally friendly, for example by incorporating cellulose and starch which microbes can break down, or by adding light-sensitive polymers that degrade in sunlight.

But Shanpu Ya and colleagues at the Polymer Science & Engineering College of Quingdao University of Science & Technology in China say these methods all have serious disadvantages. In particular, it takes too long time for polymers to break down in these ways, they claim.

Instead, they have developed a new approach that involves embedding water-absorbing resin particles about 5 micrometres in diameter throughout a chemical like styrene before it is polymerised to form a polystyrene-like material.

When the resulting solid comes into contact with water, the resin particles expand, reducing the polymer structure to a powder that should then biodegrade. The team says the rate of disintegration can even be controlled by altering the ratio of ingredients.

But a crucial factor, says the team, is that the resulting foamed polystyrene is cheaper than conventional materials and should therefore be readily adopted by cost-conscious companies that also want to be environmentally responsible.

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via newscientist