| 主权项 |
1. A method of making polylactic acid through lactide polymerization, comprising:
providing a carbon dioxide adduct of carbene; forming a reaction mixture comprising a lactide and the carbon dioxide adduct of carbene; adjusting a temperature of the reaction mixture to 50° C. to 180° C., wherein the carbon dioxide adduct of carbene has a structure represented by formula (I): wherein the dotted line together with the solid line parallel to the dotted line represent a single bond or a double bond; X1 is N; X2 is C; and wherein R1 and R2 are independently chosen from hydrogen, alkyl groups having 1 to 10 carbon atoms, alkyl groups having 1 to 10 carbon atoms and also having one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group, cycloalkyl groups having 3 to 6 carbon atoms, a halogen atom, and an adamantane group; wherein R3 and R4 are independently chosen from substituted phenyl groups having one or more substituents, wherein the substituents are the same or different, chosen from halogens, a hydroxyl group, an alkyl group, an alkoxy group, a cyano group, alkyl groups having 1-5 carbon atoms, and alkyl groups having 1-5 carbon atoms with one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group. |
