Polyurethane (PU) is a universal polymer material with excellent performance, widely used as foam materials, adhesives, coatings, rubber, etc. Nevertheless, the considerable presence of ester and ether bonds in the polyurethane backbone, combined with the hydrophilic –OH group located at the end of molecular chain, renders it intrinsically hydrophilic. This inherent hydrophilicity presents substantial constraints on its potential utilization in flexible electronic displays, wearable electronic devices, and various other fields. It is a great challenge for hydrophobic polyurethane to simultaneously achieve mechanical reinforcement. Herein, the fluorinated chain extenders were introduced into PU, which not only resulted in low surface energy but also improved the surface roughness through the microphase separation due to the difference in the solubility parameters between the fluorine-containing side chain and the main chain. The long-chain perfluorinated extender was achieved via thiol-ene click chemistry, thus regulating the fluorine content by adjusting the amount of chain extender. The low surface energy and high roughness, developed by microphase separation, make the DF_X-PU films exhibit excellent hydrophobicity (120°) and oleophobicity (121°). Additionally, the fluorine-containing side chains aggregate to form physical cross-linking points, reinforcing the mechanical properties of the film. When the fluorine-containing chain extender accounted for 10% (DF_0.5-PU), the PU film showed the best mechanical properties. Compared with the control group, tensile strength is enhanced by 165%, the toughness is increased by 287%, and the elongation-at-break was improved by 156%.

聚氨酯（PU）是一种性能优良的通用高分子材料，广泛用作泡沫材料、粘合剂、涂料、橡胶等。然而，聚氨酯主链中存在大量的酯键和醚键，与位于其上的亲水性-OH基团相结合。位于分子链末端，使其具有本质亲水性。这种固有的亲水性对其在柔性电子显示器、可穿戴电子设备和各种其他领域的潜在应用产生了很大的限制。同时实现机械增强对疏水性聚氨酯来说是一个巨大的挑战。本文将氟化扩链剂引入PU中，不仅具有较低的表面能，而且由于含氟侧链和主链之间溶解度参数的差异，通过微相分离改善了表面粗糙度。长链全氟扩链剂是通过硫醇-烯点击化学实现的，从而通过调节扩链剂的量来调节氟含量。通过微相分离形成的低表面能和高粗糙度使DF _X -PU薄膜表现出优异的疏水性(120°)和疏油性(121°)。此外，含氟侧链聚集形成物理交联点，增强了薄膜的机械性能。当含氟扩链剂占10%（DF _0.5 -PU）时，PU薄膜表现出最佳的力学性能。与对照组相比，拉伸强度提高165%，韧性提高287%，断裂伸长率提高156%。