| abstract |
Provided is a polymer obtained by homopolymerizing a lactone monomer. The polymer contains a structural unit having a lactone ring containing three or more carbon atoms, wherein at least one of the carbon atoms, except for C of —C(═O)O—, of the lactone ring forms a part of a main chain; and wherein at least one of the carbon atoms, except for C of —C(═O)O—, which forms the lactone ring and is other than the carbon atom(s) forming a part of the main chain is bridged with an atom of the main chain. |