Researchers from the US have discovered that soy bean oil could be used as a renewable feedstock for gels and resins.

Materials with self-curing, thickening, and self-gelling properties are used in many industrial applications, as caulking agents, cements or coatings. However, many current products are ultimately derived from crude oil. Alongside current developments in the use of biofuels, there is also interest in alternative and renewable sources for such materials.

Now Atanu Biswas from the United States Department of Agriculture and co-workers have discovered that one such renewable raw material can be made to spontaneously form a gel. In the absence of solvent and without the need for heating or catalyst soy bean oil undergoes an ene reaction with DEAD (diethylazodicarboxylate).

'We have been interested in combining green chemistry with the use of agricultural raw materials,' said Biswas. 'A particular interest of ours is vegetable oil, because it is relatively low-priced, abundant, and environmentally friendly,' he continued.

Biswas and colleagues hope that this work can be the beginning of a new platform for materials that need self-thickening, self-gelling and self-curing properties. 'Obviously for specific applications, some customization of end-use properties would be needed. Fortunately, there are many types of oils available that we can use to optimize given properties,' he explained.

Surya Prakash from the University of Southern California, Los Angeles, said, 'Biswas and colleagues have discovered a novel condensation of soybean oil leading to self-curing and thickening. This chemistry will have enormous promise in preparing gels, resins and adhesives using vegetable oil based bio-feedstocks.'

A future challenge will be to find an alternative to the aptly named DEAD, which is known to be toxic. However, Biswas is confident that this will be achievable. 'The key reaction for this new platform is the ene reaction. There are many reactants known to undergo ene reactions. For commercial applications, what is needed in the future is to screen these potential reactants, in view of reaction efficiency, toxicity, and economics, in order to target specific products,' he said.

Stephen Davey