Modified halloysite nanotubes ( m-HNTs) were obtained by taking methacryloxypropyltrimethoxysilane ( MPS) as the silane coupling agent,and were compounded with polyvinyl chloride ( PVC) to prepare PVC / m-HNTs nanocomposites. Then,the properties of m-HNTs were characterized by means of FT-IR,TGA and XPS. It is found that the HNTs are successfully modified by MPS. SEM photographs show that m-HNTs uniformly disperse in PVC matrix,and that the fracture surfaces of the nanocomposites exhibit severe plastic shear deformation and ductile fracture. Moreover,experimental results indicate that ( 1) m-HNTs are effective in toughening and reinforcing PVC nanocomposites,especially in improving the impact strength; ( 2) PVC /m-HNTs nanocomposites are of better mechanical properties and higher modulus,as compared with PVC /HNTs nanocomposites; and ( 3) m-
HNTs can also improve the thermal stability and rheological property of the nanocomposites.