双单体原位接枝插层法制备聚丙烯纳米复合材料的研究Ⅰ.制备、表征及力学性能的研究

用有机插层剂处理蒙脱土原土 ,制得有机蒙脱土 (O MMT) .采用双单体 (马来酸酐和苯乙烯 )原位接枝插层法 ,制备了聚丙烯 蒙脱土纳米复合材料母料 .将母料与聚丙烯基体在双螺杆上共混挤出 ,制得聚丙烯 蒙脱土纳米复合材料 (PP Montmorillonetenanocomposites,PMNC) .这是制备聚合物纳米复合材料的一种新方法 .通过X 射线衍射测试 (XRD)表明 ,有机蒙脱土片层 0 0 1面间距从原土的 1 4 9nm扩大到 2 96nm ,复合材料中蒙脱土片层 0 0 1面间距由有机蒙脱土的 2 96nm扩大到 4 0nm .力学性能测试表明 ,复合材料的力学性能明显优于PP基体 ,在提高材料拉伸强度的同时 ,缺口冲击强度也得到很大的提高 .用扫描电镜 (SEM)对材料的冲击断面形貌进行了研究 ,并从理论上分析了断裂机理 .随着蒙脱土含量的增加 ,冲击断裂形式逐渐从脆性断裂变成韧性断裂

PREPARATION OF POLYPROPYLENE/MONTMORILLONITE NANOCOMPOSITES BY THE METHOD OF in-situ GRAFT-INFTERCALATION WITH DUAL MONOMERSⅠ.PREPARTATION, CHARACTERIZATION AND MECHANICAL PROPERTIES

Organic montmorillonites ( O MMT) were prepared by treating Na montmorillonites with alkylammonium ions.The polypropylene/montmorillonite nanocomposites (PMNC) were prepared in two steps.The mother materials were synthesized by an in situ graft intercalation method with maleic anhydride and styrene firstly,then PMNC were prepared by blending PP and the mother materials by using a twin screw extruder.XRD results suggested that the layer spacing ( d 001 ) of the organic montmorillonites increased from about 1 49 nm up to about 2 96 nm,and the layer spacing ( d 001 ) of montmorillonitenm in PMNC from about 2 96 nm up to about 4 0 nm.Mechanical performance tests showed that the noched impact strength (11～12?kJ/m 2) and the tensile strength (38～39?MPa) of DMNC with lower montmorillonite contents(1wt%～3wt%) were higher than the noched impact strength (4 12?kJ/m 2) and tensile strength (33?MPa) of PP.The mechanical performance of PMNC is superior to PP's.The morphology of impact fracture surfaces were investigated by SEM and the mechanism of impact fracture was discussed.With the increasing of montmorillonite content,the mechanism of impact fracture was converted into toughness fractures from frangibility fractures.