Healable, degradable polyurethane elastomers with excellent mechanical properties based on multiple hydrogen bonds

Due to its comprehensive properties, polyurethane elastomer (PU) plays a vital role in ships, construction, transportation facilities, and other fields. However, it is challenging to design polyurethane elastomer materials with good mechanical properties, self-healing ability, and degradable ability. Herein, a kind of polyurethane elastomer based on multiple hydrogen bond crosslinking was successfully synthesized by using polycaprolactone with substantial crystallization as a soft chain segment and introducing adipic dihydrazide (ADH) and U2-diol (a ureido-pyrimidinone with two hydroxyl groups at the end) to achieve ordered hydrogen bond assembly design and control. The elastomer has good tensile strength, healability, degradability, and solubility. The maximum tensile strength and toughness of the prepared polyurethane elastomer (PUAD) were 46.34 MPa and 687.66 MJ/m3, respectively. With the increase of U2-diol content, the self-repair efficiency was greatly enhanced. After seven repair cycles, the self-repair efficiency can still reach 66.88%. In addition, the bacterial degradation test using Pseudomonas aeruginosa as a strain showed that PUAD film had excellent degradability. The dissolution test with N,N-dimethylformamide (DMF) as solvent showed that the tensile strength was almost unchanged after three dissolutions. Healable, degradable polyurethane elastomers with excellent mechanical properties based on multiple hydrogen bonds.image