Simple molecules can be used to make a biodegradable glue that is stronger than current petroleum-based mass products. And it does not have to be much more expensive, write US researchers in Science.

Eugene Chen (Colorado State University) and colleagues use beta-butyrolactone (BBL), which can be made by reacting propylene oxide with carbon monoxide. BBL in turn polymerises into poly(3-hydroxybutyrate), or P3HB for short. Some microorganisms are known to produce this naturally as a backup food source. But attempts to do something useful with it on an industrial scale have not been very successful: the stuff was too brittle.

This seems to be because there are two stereoisomers of BBL. In the polymerisation reaction, the CH3 side groups can end up at either side of the chain. If they are all on the same side, it is called a syndiotactic polymer. Alternating sides are called isotactic, and in an atactic polymer they are randomly distributed. The latter is amorphous; the first two are regular enough to easily form crystals.