We can see them in 3-D by clicking here, if you like.
With the help of a little molecule called diazobicyclo[2.2.2]octane, or DABCO for short, we can make these two polymerize. When we stir the two monomers together with DABCO, something nifty happens.
DABCO is a very good nucleophile, that is, it has a pair of unshared electrons that would just love to attach themselves to a vulnerable nucleus. Remember, electrons have negative charges, and the nuclei of atoms have positive charges. And we all know that negative charges and positive charges attract. So DABCO's electron look around, and they find a nucleus on the alcohol hydrogens of the diol. These hydrogens are vulnerable, because they are bonded to oxygen atoms. Oxygen is electronegative. This is to say it pulls electrons away from other atoms. So it pulls electrons away from its neighbor the hydrogen atom. This leaves the positive charge of its nucleus unbalanced. The electrons would have balanced the positive charge with their own negative charges, they've been sucked away by the oxygen. This leaves a slight positive charge on the hydrogen.