Macromolecules, Vol.29, No.16, 5320-5325, 1996
Preparation of a New-Type of Phosphazene High Polymers Containing 2,2’-Dioxybiphenyl Groups
The direct reaction of [NPCl2](n), with the difunctional reagent 2,2’-dihydroxybiphenyl (HOC6H4C6H4OH) and K2CO3 in tetrahydrofuran gave soluble linear phosphazene high polymers instead of the expected cross-linked products. The reaction of [N3P3Cl6] with 1, 2, or 3 equiv of HOC6H4C6H4OH and K2CO3 in acetone gave the known spiro derivatives [N3P3Cl4(O2C12H8)], [N3P3Cl2(O2C12H8)(2)], and [N3P3 (O2C12H8)(3)] without formation of bridging products, and the dichloro derivative reacted directly with parasubstituted phenols HOC(6)H(4)R and K2CO3 in acetone to give the new compounds [N3P3(OC(6)H(4)R)(2)(O2C12H8)(2)] (R = Br, COC6H5, or OCH3), without signs of replacement of the bis(aryloxy) substituents. In an analogous manner, poly(dichlorophosphazene) [NPCl2](n) reacted with HOC6H4C6H4OH and K2CO3 in THF without significant cross-linking to give, depending on the mole ratio, the soluble polymer [NP(O2C12H8)](n) (M(w) = 450 000, T-g = 160 degrees C) or the partially substituted polymers {[NP(O2C12H8)](0.35)[NPCl2](0.65)}(n) The latter were subsequently reacted with the para-substituted phenols HOC(6)H(4)R and K2CO3 in THF to give the random copolymers {[NP(O2C12H8)](0.35)[NP(OC(6)H(4)R)(2)](0.65)}(n) [R = Br, CN, COCH3, or COC6H5). The new polymers are soluble (except the CN derivative, which was sparingly soluble) white solids, with only a few ppm of unreacted chlorine, and M(w) of the order of 1 000 000 with polydispersities varying from 3 to 10. The T-g values varied with R ranging from 73 degrees C (R = CN) to 54 degrees C (R = COMe).
Keywords:CROSS-LINKING;POLYPHOSPHAZENES