使用化学工作站对制备得到生物基聚氨酯薄膜的防腐性能进行分析。生物基聚氨酯制备工艺：取乙酸丁酯和木质素或改性木质素，然后加入13 g羟基丙烯酸树脂，6.5 g固化剂，1 wt%有机锡催化剂，混合后室温下固化得到。  将聚氨酯涂布在普通Q235碳钢基材上，制备成涂层，将制备好的电极浸入3.5 wt% NaCl水溶液中，在配备屏蔽箱的化学工作站上进行电化学阻抗谱测量。每次测量前将电池平衡90分钟。EIS测量在0.01 Hz-1000 kHz 的频率范围内进行，幅度为5 mV。

The anticorrosive properties of the prepared bio-based polyurethane films were analyzed by chemical workstation. Preparation process of bio-based polyurethane: Take butyl acetate and lignin or modified lignin, then add 13 g hydroxyl acrylic resin, 6.5 g curing agent, 1 wt% organotin catalyst, and then cure at room temperature. Polyurethane was coated on ordinary Q235 carbon steel substrate to prepare the coating, and the prepared electrode was immersed in 3.5wt % NaCl solution, and the electrochemical impedance spectroscopy was measured on a chemical workstation equipped with a shielding box. Balance the battery for 90 minutes before each measurement. EIS measurements are made in the frequency range of 0.01 Hz-1000 kHz with a amplitude of 5 mV.