Formulations for chemical mechanical polishing pads with high planarization efficiency and CMP pads made therewith

A chemical mechanical (CMP) polishing pad for polishing a substrate chosen from at least one of a magnetic substrate, an optical substrate and a semiconductor substrate, the CMP polishing pad comprising a polishing layer adapted for polishing the substrate, the polishing layer being a polyurethane, the polyurethane is a product of a reaction mixture comprising (i) a liquid aromatic isocyanate component comprising one or more aromatic diisocyanates or a linear aromatic isocyanate-terminated urethane prepolymer having an unreacted isocyanate (NCO) concentration of from 20 to 40 wt. %, based on the total solids weight of the liquid aromatic isocyanate component, and (ii) a liquid polyol component comprising a) one or more polymeric polyols, and b) from 12 to 40 wt. %, based on the total weight of the liquid polyol component, of a curative mixture of one or more small chain difunctional polyols having from 2 to 9 carbon atoms, and a liquid aromatic diamine which is a liquid under ambient conditions, wherein the mole ratio of liquid aromatic diamine to the total moles of small chain difunctional polyols and liquid aromatic diamine ranges from 15:85 to 40:60, the reaction mixture comprises 48 to 68 wt. % of hard segment materials, based on the total weight of the reaction mixture, and, yet still further wherein, the CMP polishing layer has a hardness in the range of from 50 Shore A (15 Second) to 68 Shore D (15 second), and a density of from 0.45 to 0.9 g/mL.