Ring-opening polymerisation initiators type

The third type of reaction for polyester polyols synthesis is the ring opening polymerisation of cyclic esters, such as -caprolactone (reaction 8.4) or cyclic carbonates, such as ethylene glycol carbonate, propylene glycol carbonate, neopentyl glycol carbonate, etc., (reaction 8.5) initiated by diols (or polyols) and catalysed by specific catalysts [7, 16]. 

The last type of ring-opening polymerisation of lactones discussed in the present work Involves the use of organic compounds as catalysts. Although alcohols and amines are generally not nucleophilic enough to initiate polymerisation, in some cases, tertiary amines are able to initiate the polymerisation of highly reactive -lactones [30]. 

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