So it’s not a plausible mechanism for polymerization.

[espen180]

What follows is a suggested mechanism for base catalyzed acetone polymerization which is based on simple nucleophilic addition series. I have divided the mechanism into three steps, shown below.

In step 1, the reaction is initialized by a base catalyzed initiation into ketone-enolate resonance. From here, two reactions are possible.

The first, step 2a, is that the karboanion takes back the H⁺ and we end up with the original reactant which can enter into ketone-enolate resconance again through step 1.

The second, step 2b, is that the enolate attacks another acetone molecule at the electrophilic center (the carbonyl group carbon atom) and start a chain on similar addition reactions and make a polymer. The figure shows the first two of these addition reactions.

Step three is then the termination reaction where the base gives back the hydrogen kation. We gat a hydroxy group at the end, and the end product is shown below.

Is this a plausible mechanism? If not, where did I make a mistake?

All feedback is appreciated.http://img441.imageshack.us/img441/5240/polyaceton.png

EDIT: The following polymer could also be formed:

http://img168.imageshack.us/img168/8738/polyaceton2.png

 

[TeethWhitener]

Unfortunately the links are broken. However, the steps you described are all basically correct. The problem is that in step 2B, you form an aldol condensed diner instead of a polymer. There’s not really any good evidence in the literature for acetone self-polymerization. The mechanism for acetone self-condensation (to a dimer) is seen here:
https://en.m.wikipedia.org/wiki/Aldol_condensation#/media/File:Simple_aldol_reaction.png