1,3-Butanediol, polymer with alpha-hydro-omega-hydroxypoly(oxy-1,4-butanediyl) and 1,1'-methylenebis(4-isocyanatobenzene) 68797-40-0 Poly(tetramethylene glycol ether), 1,3-butanediol, 1,1'-methylenebis(4-isocyanatobenzene) polymer