The interfacial adhesion of blend of isotactic polypropylene/poly(vinyl methylether) (i-PP/PVME) has been improved by the addition of poly(propylene-g-acrylic acid) (PP-g-AA) as a compatibilizing agent. The phase morphologies of the blends are investigated by optical microscopy (OM) and lateral force microscopy (LFM). The i-PP/ PVME (80/20) blend with no addition of PP-g-AA from extrusion process shows a coarse morphology with the dispersed domain size as large as several micrometers; After the addition of 2.5% PP-g-AA in the blends, the dispersed PVME domain size decreases greatly. The addition of 5% PP-g-AA results in a homogeneous morphology. The blending of PP-g-AA with PVME reduces the crystallization temperature of PP-g-AA, which is different from that of blending i-PP with PVME. The increase of the interfacial adhesion is attributed to the specific intermolecular interaction between the acrylic acid group of PP-g-AA and the ether group of PVME. The specific interaction is studied by Fourier transform infrared spectroscopy. (c) 2006 Wiley Periodicals, Inc.