聚醚铵改性蒙脱土对纳米蒙脱土/聚丙烯复合材料微观结构的影响

采用自制的2种大层间距(层间距分别为6.72nm和8.66nm)的聚醚铵(POP)改性蒙脱土(MMT)OMMT1和O-MMT2,通过共混法与增容剂马来酸酐接枝聚丙烯(PP-g-MAH)或聚丙烯(PP)复合,考察了共混方法、共混时间、POP改性MMT的层间距及PP-g-MAH对MMT/PP-g-MAH和MMT/PP复合材料微观结构的影响。研究结果表明:由于O-MMT1具有较大的层间距,在溶液共混和熔融共混中,均能使MMT在PP-gMAH基体中发生剥离;随着共混时间延长,O-MMT1由插层型经过过渡状态向剥离型转变,最终可以获得完全剥离的纳米MMT/PP-g-MAH复合材料;在溶液共混的过渡态中存在大量"双层结构"的MMT片层;具有更大层间距的O-MMT2以及PP-g-MAH的加入均能更有效地促进MMT在PP基体中的剥离,从而获得完全剥离的纳米MMT/PP复合材料。

Effect of montmorillonite modified by poly (oxypropylene) amine hydrochlorides on microstructure of nano-montmorillonite/polypropylene composites

Two kinds of self-prepared montmorillonite (MMT) modified by poly (oxypropylene) amine hydrochlorides (POP) with large basal spacing, O-MMT1 and O-MMT2 (the basal spacing is 6.72 nm and 8.66 nm, respectively), were added into polypropylene-grafted-maleic anhydride (PP-g-MAH) or polypropylene (PP) by blending methods. The effects of blending methods, blending time, basal spacing of the POP modified MMT and PP-g-MAH on the microstructure of MMT/PP-g-MAH and MMT/PP composites were investigated. The results show that O-MMT1 with large basal spacing benefits the exfoliation of MMT in PP-g-MAH matrix during the solution blending and melt blending process. With the extension of blending time, O-MMT1 turns to the exfoliated state through transitional state from inserted layer type and MMT/PP-g-MAH composites with completely exfoliated state are obtained finally. A lot of MMT layers with "bilayer structure" are found at the transitional state in the solution blending process. In addition, the addition of O-MMT2 with larger basal spacing and PP-g-MAH, both facilitate the exfoliation of MMT in PP matrix so that the completely exfoliated nano-MMT/PP composites are obtained.