By introducing novel stimuli-responsive Diels–Alder (DA) diol into polymer chains, a series of environmentally friendly, self-healing, and recyclable waterborne polyurethanes based on DA/retro-DA reactions (WPU-DA-x) were successfully prepared through a modified acetone process. The properties and appearance of the resultant WPU-DA-x latex were analyzed by considering particle size and zeta potential which show these dispersions with an outstanding storage stability. Simultaneously, the molecular mechanism of the self-healing behavior was extensively investigated via 1H NMR, FT-IR, and UV–vis spectroscopies exhibiting effective reversibility of the DA/retro-DA chemistry. Moreover, WPU-DA-x films with outstanding mechanical performance show an excellent self-healing capability due to the couple/decouple process of the DA reactions, and the self-healing process was qualitatively and quantitatively studied. At the same time, the networked WPU-DA-x could be recycled via hot-pressing and solution casting. At last, the thermal stability of WPU-DA-x films was distinctly enhanced, as shown by the TGA results. The fruitful outcomes indicate that WPU-DA-x exhibited a great potential application as a smart material.

Two kinds of dimethylpolysiloxane, KF-6001 and X-22-176-DX, were used to modify polyurethane.

Waterborne fluorinated polyurethanes (WFPUs) based on hydroxyl‐terminated poly(fluoroalkyl methacrylate)s (HTPFMAs) with different main‐chain lengths were synthesized. The structure of HTPFMA was characterized using 1H NMR spectroscopy, measurements of hydroxyl values and gel permeation chromatography. The microstructures of WFPUs were investigated using Fourier transform infrared spectroscopy, which indicated that hydrogen bonding interactions in hard segments of WFPUs were enhanced by the introduction of HTPFMA and increased with increasing main‐chain length of HTPFMA. The results of X‐ray diffraction demonstrated that increasing the main‐chain length of HTPFMA resulted in an increase of crystallinity in hard segments. Differential scanning calorimetry revealed that the melting temperature of micro‐crystallites in hard segments and the microphase separation increased with an increase of HTPFMA main‐chain length. Dynamic mechanical analysis and scanning electron microscopy also confirmed that HTPFMA with longer main‐chain length can promote the extent of microphase separation of WFPUs between soft and hard domains. The mechanical properties of WFPUs were improved due to the increase of microphase separation with increasing HTPFMA main‐chain length. © 2018 Society of Chemical Industry