聚合物修饰蒙脱土杂化水基聚氨酯树脂的制备和性能

Preparation and Properties of Waterborne Hybrid Polyurethane Resins Containing Polymer Modified Montmorillonite

采用端羟基阳离子聚氨酯低聚物作为插层剂对钠基蒙脱土(MMT)进行有机改性,制备出羟基修饰的聚合物蒙脱土。将该改性活性有机蒙脱土(OMMT)作为增强体,制备出聚氨酯纳米片层粒子复合的杂化树脂。以封端型六亚甲基二异氰酸酯(HDI)三聚体为交联剂与上述复合树脂混合,经机械剪切、水乳化得到纳米杂化电泳树脂,经电泳工艺制备出聚氨酯漆膜,漆膜的耐化学腐蚀性得到改善。采用广角X射线衍射(WXRD)、傅里叶变换红外(FT-IR)、热重(TG)分析研究了新型有机蒙脱土的结构与性能。用透射电子显微镜(TEM)表征了杂化聚合物及有机蒙脱土的形态。同时研究了有机蒙脱土添加量对漆膜性能的影响。结果表明:钠基蒙脱土经端羟基阳离子聚氨酯改性后,其层间距由原来的1.309 nm扩大到2.154 nm,当其质量分数为0.3%时,电泳漆膜的耐酸性和耐水性得到较大的改善。

Hydroxyl terminated cationic polyurethane oligomers were used as intercalating agent to modify tile Na-montmorillonite （Na-MMT） to form the hydroxyl-modified montmoril- lonite. The novel active organic montmorillonite （OMMT） was used as the reinforcing body of polyurethane matrix to prepare the cationic polyurethane hybrid resins. The hexamethylene di- isocyanate （HDI） trimer as the cross-linking agent was combined with the hybrid resin and then emulsified in water to give the nano-hybrid eleetrophoresis resin. A series of polyurethane films were prepared by the electrophoresis process, showing an improved chemical corrosion resistance. Wide-angle X-ray diffraction （WXRD） , Fourier transform infrared （FT-IR） and thermo-gravimetry （TG） were used to study the structure and properties of the novel organic montmorillonite. The morphology of the polyurethane composites was characterized via transmodified by hydroxyl-terminated cationic polyurethane, furthermore, the properties such as acid resistance and water resistanee of the electrophoresis film were improved significantly when the mass fraction of OMMT was 0. 3%.