Their new insights make it possible to synthesize a material with predetermined properties, such as elasticity or hardness.

Polypropylene is so ubiquitous one might call it the king of plastics. In terms of production volume, it is second only to polyethylene. By tweaking its molecular structure, polypropylene can be used to manufacture materials with a wide range of features, from elastic bands to high-impact plastic. However, the relationship between the polymer's chemical structure and its mechanical properties was not fully understood.

A polypropylene chain consists of a backbone of carbon atoms with attached hydrogen atoms. Every other carbon atom in the chain has a methyl group attached to it. Two adjacent carbon atoms in the chain with the hydrogen atoms and the methyl group bonded to them constitute a repeating unit called propylene, or propene. The spatial configuration of the macromolecule — the polymer chain — is determined by the mutual orientation of the methyl groups in the chain : If they are all on one side, the molecule is said to be isotactic.