Factors Affecting Polymerizability

Several factors are known to affect the ROP of cyclic esters. The main factors are the reaction conditions, i.e., the nature of the initiator, type of solvent and reaction temperature, and also the ring size of the monomer used and the substituents on the monomer ring [105-107] Cyclic esters of four-, seven-, and eight-membered rings polymerize, whereas the five- membered ester does not. In the case of six-membered rings, the polymerizability depends on the substituents [105],... 

As would be anticipated, the nature of substituent groups has a profound influence on the reactivity and polymerizability of an NCA. The rates of reaction between NCA and base molecules are affected by stereochemical and electronic factors further, in suitable circumstances, interactions between propagating species and side-chain groups may occur. 

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