Polyurethane (PU) belongs to a class of special polymeric materials with hydrogen bonds, which has the potential for self-healing ability. In the present work, by introducing polypropylene glycol (PPG) blocks with high segment mobility and different block lengths on the ends of PU chains, the PUs with adjustable self-healing ability were successfully obtained. The self-healing ability of the PUs firstly increases with the increase of the PPG block lengths, but then decreases. This phenomenon can be attributed to the combined effects of the density of hydrogen bonds and the mobility of PPG segments. At first, the increase of the PPG block length leads to the improvement of mobility of PU chains, which is beneficial for the enhancement of the self-healing. However, the further increase of the PPG block length results in the reduction in the hydrogen bond density, finally leading to the decrease of the self-healing ability of the PUs.

聚氨酯（PU）属于一类具有氢键的特殊聚合材料，具有自我修复的潜力。在目前的工作中，通过在PU链的末端引入具有高链段迁移率和不同嵌段长度的聚丙二醇（PPG）嵌段，成功获得了具有可调自修复能力的PU。PU的自愈能力首先随着PPG块长度的增加而增加，然后降低。这种现象可归因于氢键密度和PPG链段迁移率的综合作用。首先，PPG块长度的增加导致PU链迁移率的提高，这有利于增强自我修复。然而，