| 摘要 |
Poly(aryloxyphosphazene) copolymers and foams thereof having a significant portion of C1 - C4 alkoxyphenoxy groups are described. The copolymers consist of the units which occur in a nonregular fashion and are represented by the following general formulas: <IMAGE> +TR <IMAGE> wherein R1 represents a C1 - C4 linear or branched alkyl radical in the ortho-, meta-, or para-position, and R2 represents hydrogen, a C1 - C10 linear or branched alkyl radical, or a C1 - C4 linear or branched alkoxy radical substituted on any sterically permissible position on the phenoxy group, with the proviso that when R2 is alkoxy, OR1 and R2 are different. The copolymers of this invention may contain small amounts of randomly distributed units in addition to the repeating units described above, these additional units containing reactive sites enabling the properties of the copolymers to be modified by crosslinking and/or curing. The copolymers are elastomers, have desirable tensile strengths and may be used to form flexible or semirigid foams. The copolymers are extremely fire retardant and produce low smoke loads, or essentially no smoke, when heated in an open flame.
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