Biomass-resource-derived polyurethane, method for producing same, and biomass-resource-derived polyester polyol

A biomass-resource-derived polyurethane, comprising, in reacted form:

• (I) a polyester polyol unit having a number average molecular weight of 500 to 4,000 and comprising, in reacted form:
• an organic acid comprising three or more active hydrogen groups per molecule and having a pKa value at 25° C. of not more than 3.7;
• a dicarboxylic acid unit comprising a dicarboxylic acid other than the organic acid, wherein at least a portion of the dicarboxylic acid is derived from biomass resources;
• and
• an aliphatic diol unit,
• wherein a content of the organic acid is more than 0% by mole and not more than 0.09% by mole relative to the dicarboxylic acid unit;
• and
• (II) a polyisocyanate unit.