# What's the monomer in a polycarbonate?

I know what the repeating unit is, but what's the monomer in a polycarbonate?

• A polymer name is defined by the repeating unit. Polycarbonates (which is a large group of polymers) further are a nice example where the same repeating unit can be created in a number of ways, from different monomers. Your question is a bit ambigous with regard to this. Please elaborate. What polycarbonate are we talking about? – Karl Jul 15 '18 at 21:10
• Not all polymers are made of single monomers. Polycarbonates usually consist of at least 2 so asking what "the" monomer is isn't quite correct. – matt_black Jul 16 '18 at 13:06

Like Dr J said there is no single polycarbonate polymer, the most common one is formed from phosgene (or another carbon dioxide reagent) and bisphenol A. The repeating unit is $\ce{C6H4C(CH3)2C6H4-O-C(=O)-O -}$