poly[oxy(methyl-1,2-ethaandiyl)], α-(1-oxooctadecyl)-ω-hydroxy- (15 mol PO gemiddelde molaire verhouding) ###>Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-(1-oxooctadecyl)-.omega.-hydroxy- (15 mol PO average molar ratio)