纳米蒙脱土的制备及在超高分子量聚乙烯中的应用

采用插层聚合方法,用苯乙烯(ST)、丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)等单体,对蒙脱土进行了层间改性,并与聚合物共混挤出制备了纳米复合材料。通过X射线衍射仪、转矩流变仪、红外光谱仪等仪器,对改性蒙脱土的层间结构进行的表征可知,随着单体插层、层间聚合、熔融共混的进行,蒙脱土的层间距从1.470 nm逐渐增大至2.643 nm,最终消失,表明蒙脱土发生了层间剥离,与子聚合物形成了纳米复合材料;改性前后蒙脱土的红外谱图在1465~1440 cm-1和2910~2830 cm-1处的特征峰发生了明显的变化,这从分子结构上证明了蒙脱土的改性。同时比较了添加不同改性蒙脱土的超高分子量聚乙烯的扭矩变化,3种单体改性的蒙脱土均能有效降低聚合物扭矩,其中苯乙烯单体插层聚合改性的蒙脱土对聚合物体系扭矩影响最大。

Preparation of Nano-montmorillonite and Its Application in UHMWPEs

By intercalation polymerization with styrene(ST),acrylamide(AM),methyl acrylamide trimethyl ammonium chloride(DMC) monomer,a layer of montmorillonite was modified,and the polymer blend nanocomposites were prepared by an extrusion method.Utilizing X-ray diffraction,torque rheometer,infrared spectrometer and other instruments,the modified montmorillonite layer structure was characterized.The results showed that as monomer intercalation,layer polymerization,and melt blending were fulfilled,the montmorillonite interlayer gradually increased from 1.470 to 2.643 nm,ultimately disappeared.It indicated that the dissection of montmorillonite interlayers occurred,and a formation of polymer nano-composites.The infrared spectrum of the modified montmorillonite illustrated in a characteristic peak in a significant change between 1 465 ～ 1 440 cm-1 and 2 910 to 2 830 cm-1.The result proved that the montmorillonite was modified at the level of molecular structure.UHMWPEs were added with different amount of the modified montmorillonite.And their torque values changed.Among three types of the monomer modified montmorillonites used in the present study,the one modified with styrene monomer polymerization intercalation can effectively reduce the torque value of the UHMWPE.