Abstract In the present work, the bio-based hyperbranched polyol (COHBP) was prepared by using castor oil and dimethylol propionic acid (DMPA). The molecular structure of COHBP was determined by FTIR and NMR. Polyurethanes of castor oil (PU−COs) and castor oil based hyperbranched polyol (PU−COHBPs) were prepared by using various diisocyanate as cross-linking agent at NCO: OH, ratio of 1.2:1, in presence of dibutyltin dilaurate (DBTDL) as catalyst. Finally, these polyurethanes were coated on glass plate and mild steel panels. Thermal behavior of PU−COs and PU−COHBPs were studied by thermo-gravimetric analyzer (TGA). The mechanical properties of the coated panels were estimated by performing various tests such as cross-cut adhesion, scratch resistance, impact resistance, mar resistance, flexibility, and pencil hardness. Chemical resistance property of coating was evaluated by immersion method. The polyurethanes films were characterized by gel content. The corrosion rate of each coating plate was determined by electrochemical method. The surface morphology of coating films was studied by AFM and SEM, while their crystallinity was estimated by XRD analysis. The properties of PU−COHBPs were compared with PU−COs. It was found that PU−COHBPs showed excellent coating performance as compared to PU−COs.

中文翻译：

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聚氨酯涂料中生物基超支化多元醇的合成及性能

摘要 在目前的工作中，使用蓖麻油和二羟甲基丙酸（DMPA）制备了生物基超支化多元醇（COHBP）。COHBP的分子结构由FTIR和NMR确定。在二月桂酸二丁基锡 (DBTDL) 的存在下，使用各种二异氰酸酯作为交联剂，NCO: OH 的比例为 1.2:1，制备了蓖麻油 (PU-COs) 和蓖麻油基超支化多元醇 (PU-COHBPs) 的聚氨酯作为催化剂。最后，将这些聚氨酯涂在玻璃板和低碳钢板上。通过热重分析仪 (TGA) 研究了 PU-COs 和 PU-COHBPs 的热行为。涂层板的机械性能通过进行各种测试来评估，例如横切附着力、抗划伤性、抗冲击性、耐擦伤性、柔韧性和铅笔硬度。采用浸渍法评价涂层的耐化学性。聚氨酯薄膜的特征在于凝胶含量。用电化学方法测定各镀层板的腐蚀速率。通过AFM和SEM研究涂层膜的表面形貌，而通过XRD分析估计它们的结晶度。PU-COHBPs 的性能与 PU-COs 进行了比较。结果表明，与 PU-COs 相比，PU-COHBPs 表现出优异的涂层性能。