摘要： 选用甲苯二异氰酸酯(TDI)、端羟基聚丁二烯(HTPB)、二羟甲基丙酸(DMPA)、封闭剂等合成水性封闭型聚氨酯预聚物,用作橡胶表面的涂层。通过傅里叶变换红外光谱(FT-IR)对封闭过程进行了跟踪监测,并对苯酚和甲乙酮肟(MEKO)的封闭效果进行了比较;对不同交联剂含量下的涂膜性能和机械性能进行了测定。研究发现:甲乙酮肟具有较短的封闭时间和较低的解封温度,而涂膜的硬度和拉伸强度随交联剂用量的增加而提高,充分的交联剂用量可以得到拉伸强度18.9 MPa,断裂延长率324%的涂膜,可以满足橡胶涂料的性能要求。

关键词: 水性聚氨酯, 橡胶涂料, 封闭型聚氨酯, 甲乙酮肟, 高温固化

Abstract: Toluence diisocyanate(TDI), hydroxyl-terminated polybutadiene(HTPB), dimethylol propionic acid( DMPA ) and blocking agents were used to synthesize blocked waterbome polyurethane as rubber coatings. The bocking reaction was traced by FT-IR with attenuated total reflectance(FTIR-ATR). The blocking effects of phenol and methyl ethyl ketoxime(MEKO) was compared. The coating properties with difterent amount of crosslinker were measured. It was found that MEKO had a shorter blocking time and a lower unblocking temperature. The hardness and tensile strength of coating film were increased with the increasing of crosslinker level. With the adequate amount of crosslinker, the tensile strength of the coating could reach 18.9 MPa and the fracture elongation 324%, which could meet the requirement of rubber coatings.

Key words: waterborne polyurethane, rubber coatings, blocked polyurethane, methyl ethyl ketoxime, high temperature curing