The functional group
![[*:1]C([*:2])=C([*:3])[*:4]](https://www.chemicalforums.com/SMILES/12242df23fb6a6210791.png)
polymerises by addition through the double bond into
![[*:1]C([*:2])C([*:3])[*:4]](https://www.chemicalforums.com/SMILES/fb518fe80cbd9992db75.png)
of which there are n repeat units.
My question is, what happens if we polymerise a diene by addition under the same conditions? Will you get a network of cross-chains going, or is one C=C or the other selected as the one which will then added to (the other staying intact)?