Polyphosphazenes cyclomatrix

The molecular architecture of a polyphosphazene has a profound influence on properties. For example, linear and tri-star trifluoroethoxy-substituted polymers with the same molecular weight (1.2 x 104 or higher) have strikingly different properties.138 The linear polymers are white, fibrous materials that readily form films and fibers, whereas the tri-arm star polymers are viscous gums. One is crystalline and the other is amorphous. Cyclolinear polymers are usually soluble and flexible. Cyclomatrix polymers are insoluble and rigid. Linear polymers can be crystalline, but graft or comb polymers are usually amorphous. 

Figure 1 Different types of polyphosphazenes including linear classical macromolecules (1), star structures (2), block copolymers (3), cyclolinear polymers (4), and comb or graft copolymers (5) and (6). Not shown are cyclomatrix materials in which cyclic trim eric rings are connected in three dimensions ...

Introduction.— This section deals only with linear polyphosphazenes neither cyclolinear or cyclomatrix polymers are included, nor is reference made to mixed organic-inorganic polymers. Numerous reviews related to the preparation, physical properties, and application have been published. Readily accessible papers are mentioned here. " ... 

Fig. 13. Polymers containing cyclic phosphazene trimers (a) polylalkenyl-cyclophosphazene), (b) cyclolinear polyphosphazene, and (c) cyclomatrix material.

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