Flory convention

In polymer science, the Flory convention is a convention for labelling rotational isomers of polymers. It is named after Nobel Prize-winning Paul Flory.{{cite journal |author=Flory PJ |title=Molecular Size Distribution in Three-Dimensional Polymers: I, Gelation |journal=J. Am. Chem. Soc. |volume=63 |issue=11 |pages=3083 |year=1941 |doi=10.1021/ja01856a061}}Morris PJT (1986). "Polymer Pioneers: A Popular History of the Science and Technology of Large Molecules". Center for History of Chemistry, Philadelphia.

The convention states that for a given bond, when the dihedral angle formed between the previous and subsequent bonds projected on the plane normal to the bond is 0 degrees, the state is labelled as "trans", and when the angle is 180 degrees, the angle is labelled as "cis".