Polyurethane dispersions

An inkjet ink, comprising:

• an aqueous ink vehicle;
• a pigment;
• and
• a polyurethane dispersion, comprising a polyurethane with a polymeric ionic side chain and a polymeric non-ionic side chain, the polyurethane formed of polymerized monomers, comprising:
• a diisocyanate,
• a first polymeric diol comprising a first polymer chain replacing a hydrogen atom of a thiol group of a 1-thioglycerol molecule, the first polymer chain comprising a block of a polymerized ionic group-containing vinyl monomer, and
• a second polymeric diol comprising a second polymer chain replacing a hydrogen atom of a thiol group of a 1-thioglycerol molecule, the second polymer chain comprising a block of a polymerized non-ionic vinyl monomer, wherein the second polymer chain is devoid of ionic groups.

An inkjet printing system, comprising:

• an intermediate transfer member;
• an inkjet ink comprising:
• an aqueous ink vehicle,
• a pigment, and
• a polyurethane dispersion, comprising a polyurethane with a polymeric ionic side chain and a polymeric non-ionic side chain, the polyurethane formed of polymerized monomers, including:
• a diisocyanate,
• a first polymeric diol comprising a first polymer chain replacing a hydrogen atom of a thiol group of a 1-thioglycerol molecule, the first polymer chain comprising a block of a polymerized ionic group-containing vinyl monomer, and
• a second polymeric diol comprising a second polymer chain replacing a hydrogen atom of a thiol group of a 1-thioglycerol molecule, the second polymer chain comprising a block of a polymerized non-ionic vinyl monomer, wherein the second polymer chain is devoid of ionic groups;
• and
• an inkjet printhead positioned to jet the inkjet ink onto the intermediate transfer member.