Phosphacyclic monomers

Coordination polymerisation of heterocyclic monomers comprises polymerisation and copolymerisation processes of such monomers as oxacyclic monomers, especially epoxides [2,61-71], thiacyclic monomers like episulphides [72-76], azacyclic monomers [77,78] and phosphacyclic monomers [79]. Monomers with an exocyclic oxygen atom, such as cyclic esters like lactones [80-90] and lactide [90-92], cyclic acid anhydrides [93-98], cyclic carbonates [99,100] and related monomers, belong to oxacyclic monomers undergoing coordination polymerisation or copolymerisation. 

An interesting example of the coordination polymerisation of a phosphacyclic monomer is represented by the polymerisation of oxyphosphonoyloxytrimethy-lene (2-hydro-2-oxo-l,3,2-dioxaphosphorinane) in the presence of triisobutyla-luminium as the catalyst [181,182], This polymerisation, carried out at a temperature of 25 °C, produced, in relatively high yield, poly(oxyphosphonoy-loxytrimethylene) which appeared to be a high molecular weight polymer (Table 9.2). 

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