{HEAD ~ Preferred polymers} of formula further include polymers where R is {TAIL ~ a polyalkylene oxide}, i.e., R together with the oxygens to which it is attached forms a bridging polyol, such as polytetramethylene ether, polypropylene oxide, polyethylene oxide, other polyalkylene oxides, including polyalkylene oxides containing mixed length alkylenes 
{ HEAD ~ Preferred polymers } of formula further include polymers where R is { TAIL ~ a polyalkylene oxide } , i.e. , R together with the oxygens to which it is attached forms a bridging polyol , such as polytetramethylene ether , polypropylene oxide , polyethylene oxide , other polyalkylene oxides , including polyalkylene oxides containing mixed length alkylenes
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