聚氨酯改性有机硅树脂的制备与性能研究

摘要

以4,4-二苯基甲烷二异氰酸酯、聚酯多元醇合成聚氨酯预聚体,用3-氨基丙基三乙氧基硅烷封端后,再与硅氧烷共水解缩合制备聚氨酯改性的有机硅树脂.采用红外光谱(FT-IR)和核磁共振(29Si-NMR)分析证实了改性硅树脂的结构.热失重(TG)结果表明,在空气气氛下,硅树脂的起始分解温度在300℃左右.当聚氨酯质量分数为10％的改性树脂制成清漆涂层后,耐化学性能良好,且在240℃下烘烤48 h后,附着力、抗冲击性能仍保持良好.%A series of polyurethane-modified silicone resins have been prepared using phenyltrimethoxysilane, di-phenyldimethoxysilane, methyltriethoxysilane, and dimethyldiethoxysilane, and polyurethane prepolymer-which was synthesized from methylene diphenyl diisocyanate ( MDI) and polyester polyols, and finally endcapped with KH550. FT-IR and 29Si-NMR spectroscopy confirmed the chemical composition and structure of the modified resins. Thermogravimetric (TG) analysis showed that the modified silicone resins exhibited excellent heat resistance with an onset degradation temperature of 300 °C in air. Modified silicone resin paints with 10% polyurethane content can cure at room temperature, and have good impact and adhesion properties after heating at a temperature of 240 ℃ for 48 hours.