Effect of compatibilizer on micromehanical deformations and morphology of dispersion in PP/PDMS blend

Role of maleic anhydride grafted polypropylene (PP‐g‐MAH) in interface modification in polypropylene (PP)/poly(dimethylsiloxane) (PDMS) elastomer blend has been investigated in this article through its effects on morphology of dispersion, micromechanical deformations such as voiding, crazing, shear yielding, fibrillation, and tensile behavior. During tensile deformation, PP/PDMS blend without the compatibilizer showed debonding at the elastomer‐matrix interface and it induced shear yielding and subsequently fibrillation in the matrix. The compatibilizer improved the interfacial adhesion between the PDMS domains and PP matrix, which prevented the debonding at elastomer‐matrix interface and the resulting shear yielding, and fibrillation was absent and rather caused extensive crazing in the matrix. Addition of PP‐g‐MAH reduced the size of dispersed PDMS domains, and narrowed the domain size distribution, which is attributed as an effect of interfacial adhesion produced by PP‐g‐MAH. Stress–strain curve and fibrillation also show similar effect of the interfacial adhesion caused by the compatibilizer. All these observations consistently lead to conclude that PP‐g‐MAH acts as a good compatibilizer for PP/PDMS blend. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007