Facile synthesis of a room-temperature liquid dihydrazide from vegetable oils for coatings and polyurethane films

Biobased dihydrazides represent promising renewable building blocks for the development of sustainable, high-performance materials. However, their broader practical application is hindered by poor solubility, high melting points, and processing challenges, all of which originate from the intrinsically dense hydrogen bonding networks and tightly packed crystalline arrangements of conventional linear analogues. Here, we report the synthesis of a Y-shaped dihydrazide (YDH), which is readily produced in only two steps from vegetable-oil-derived methyl oleate, achieving a bio-content of 64 %. Thanks to its distinctive Y-shaped architecture, YDH disrupts intermolecular hydrogen bonding and diminishes crystalline packing, leading to its liquid state at room temperature and exceptional solubility in both polar and moderately polar solvents. These properties enable YDH to serve not merely as a minor additive but as a principal building block for synthesizing polyurethane (PU) films, with bio-contents reaching up to 30.2 %. Moreover, YDH supports the straightforward fabrication of self-cleaning coatings and allows precise tuning of PU mechanical properties—ranging from rigid, high-strength films to highly elastic materials suitable for flexible substrates. This study establishes YDH as an emerging building block that unlocks the full potential of biobased dihydrazides and paves the way for the development of advanced biobased materials, including, but not limited to, high-performance coatings and PU films. A Y-shaped dihydrazide, synthesized via a facile two-step synthetic route from vegetable oils, remains liquid with high solubility at room temperature, serving as a versatile building block that expands the applicability of biobased dihydrazides. • Synthesized a novel Y-shaped dihydrazide from renewable vegetable oils. • Achieved a room-temperature liquid state with broad solvent compatibility. • Enabled PU films with 30.2 % bio-content using the Y-shaped dihydrazide as the sole biobased component. • Created biobased self-cleaning coatings derived from the Y-shaped dihydrazide.