**2. Materials and Methods**

## *2.1. Materials*

Hexafluoropropylene trimer (HFPT) was purchased from Quzhou Chemical Industry Co., Ltd. (Quzhou, China). p-Hydroxybenzyl alcohol, potassium carbonate (K2CO3), tetrahydrofuran (THF), toluene diisocyanate (TDI), 1,4-butanediol (BDO), N,N-dimethylformamide (DMF) and ethanol (C2H5OH) were supplied by Aladdin Chemical Reagent Co., Ltd. (Shanghai, China). C8 waterproofing agent was provided by Taifu Chemical Technology Co., Ltd. (Shanghai, China).
