def split_materials_mesh(selected):
    me=Blender.Object.Get(selected)
    mesh=me.getData()
    List_fragment=[]
    Materials=mesh.getMaterials(0)
    for mat in Materials:
       List_fragment.append([])
    for f1 in mesh.faces:
       List_fragment[f1.materialIndex].append(f1) 
    if len(List_fragment)>1:
      for nouveau in List_fragment:
        fragment=Blender.NMesh.GetRaw()
        for f1 in nouveau:
           for v2 in f1.v:
              if v2 not in fragment.verts:
                   fragment.verts.append(v2)
        fragment.faces=nouveau
        fragment.materials=[Materials[List_fragment.index(nouveau)]]
        names = NMesh.GetNames()
        n=0
        nom_prov=mesh.name+'%s' % List_fragment.index(nouveau)
        while nom_prov in names:
              nom_prov=nom_prov+'%s' % (List_fragment.index(nouveau)+n)
              n+=1 
        ob=NMesh.PutRaw(fragment,nom_prov,1)
        ob.setMatrix(me.getMatrix()) 
    print "nothing to do" 

try:
  list=Blender.Object.GetSelected()[0] 
  if list.getType()=='Mesh':
      split_materials_mesh(list.name ) 
  else:
      pass
except:
   print 'perhaps not a mesh or no object selected'

Blender.Redraw()