Other Nucleophilic ROP Catalysts

The activation of initiating and propagating alcohols by strong nonionic bases can be utilized to enable the polymerization of strained cyclic ester monomers, such as lactide. As mentioned above, both DBU and MTBD are highly active catalysts for this ROP process, providing DP 500 PLAs within a few minutes at room temperature and 1 mol% catalysts loadings. These amidine and guanidine compounds have comparable pX, values =24.3 and 25.4, respectively), and a 

The application of guanadinium acetate as a catalyst for the ROP of lactides and lactones has also been demonstrated [41, 42], Polymerization proceeds at 110°C 

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