聚氨酯/有机蒙脱土纳米复合材料的结构与性能 Ⅰ·水基端羟基阳离子聚氨酯改性蒙脱土

Structure and properties of polyurethane/organic montmorillonite nanocomposites Ⅰ.Modification of montmorillonite with water-based hydroxyl terminated cationic polyurethane

合成了一系列不同相对分子质量的水基端羟基阳离子聚氨酯(WHTCPU),用其作为插层剂对蒙脱土(MMT)进行有机改性,通过阳离子交换得到含有活性羟基官能团的有机MMT。用广角X射线衍射、傅里叶变换红外光谱、透射电子显微镜、原子吸收光谱和显微电泳法等对改性后MMT的结构、性能进行了分析表征。结果表明,经WHTCPU改性的MMT是含有活性羟基官能团的有机MMT;当NCO/OH的摩尔比为1.5/2时,MMT层间距由原来的1.264 nm扩大到2.025 nm,此时有机MMT的阳离子交换能最低;经过WHTCPU改性的MMT粒子的电性得到反转。

The montmorillonite （MMT） was organically modified by a series of water-based hydroxyl terminated Cationic polyurethane （ WHTCPU ） which had different of relative molecular mass, and organic MMT（OMMT） with reactive hydroxyl group was obtained by cation exchange process. The structure and properties of OMMT were characterized by wide angle X-ray diffraction, Fourier transform infrared spectrometer, transmission electron microscopy, atomic absorption spectrometry and micro-electrophoresis. The results showed that OMMT contained reactive hydroxyl group when MMT was modified with WHTCPU. The inter lamellar space of OMMT was enlarged to 2. 025 nm from 1. 264 nm when the ratio of NCO/OH was 1.5/2 because of the intercalation of WHTCPU between the layers of MMT. The concentration of exchangeable cation was lower when the mole ratio of NCO/OH was 1.5/2. The result of micro-electrophoresis experiment showed that the particles of WHTCPU/MMT displayed positive electricity.