Nonlinear-optical phosphazenes

A number of liquid crystalline polyphosphazenes with mesogenic side groups have been prepared (48—50). Polymers with nonlinear optical activity have also been reported (51). Polyphosphazene membranes have been examined for gas, liquid, and metal ion separation, and for filtration (52—54). There is interest in phosphazene—organic copolymers, blends, and interpenetrating polymer networks (IPNs) (55—61) to take advantage of some of the special characteristics of phosphazenes such as flame retardance and low temperature flexibility. A large number of organic polymers with cydophosphazene substituents have been made (62). 

C). The nonlinear optical effects were studied at 633 nm at room temperature. In another example of substitution reactions of [NPCl2] the sodium salt of 7-(2-hydroxyethoxy)-4-methylcoumarin was used to incorporate photosensitive coumarin groups on the main phosphazene chain to obtain the cross-linkable polymer (190) (average ca. 10, Tg = 67 °C) that is stable up to 280 °C and that, under XJV irradiation, undergoes a [2 -l- 2] cycloaddition to form insoluble cross-linked curable films. The related poly[(bis(3-acetylcoumarin-o-aminoben-zoylhydrazone)phosphazene] has also been reported. ... 

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