| 摘要 |
Organosilicone polymers are provided containing monofunctional units (R)3SiO1/2 and reoccurring difunctional units (R)(Q)SiO2/2 and (R)(E)SiO2/2, as essentially the sole types of units or in combination with reoccurring difunctional dialkylsiloxy units, R2SiO2/2, where R of said units is alkyl, Q is -O-R DEG -CN or -R DEG -CN, R DEG being bivalent alkylene, and E is a polyoxyalkylene block, at least 75 weight percent of the oxyalkylene content of the polymers being constituted of oxyethylene and the mole ratio of the (R)3SiO1/2:(R)2SiO2/2:(R)(Q)SiO2/2:(R)(E)SiO2/2 units being about 2:0-20:2-20:2-30, provided the combined weight of said units is constituted, on the average, of from about 50 to about 85 weight percent of said polyoxyalkylene blocks (E). The polymers of the invention are effective stabilizers of flexible polyester polyol-based polyurethane foams and offer particular advantage in the formation of flame-retarded foams. Also described is a particular class of cyano-substituted polyalkylsiloxane hydrides which are useful in the preparation of the aforesaid polymers.
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