Pan-milling preparation of polypropylene-graft-maleic anhydride and its compatibilizing effect on polyamide 6/polypropylene blend

Abstract

By pan-milling at ambient temperature, maleic anhydride (MAH) was mechanochemically grafted onto polypropylene (PP) in solid state without the aid of initiator. FT-IR confirmed the formation of PP-g-MAH. The obtained PP-g-MAH was applied as compatibilizer for polyamide 6/PP blend. Morphological analysis shows that the microstructure was well modified by incorporating PP-g-MAH into PP/PA6. PP phase has a dimension reduced a lot and more uniform dispersion in PA6 matrix. The equilibrium torque of compatibilized blend increased too. Mechanical tests show that PP-g-MAH substantially improved the mechanical properties of PA6/PP blend. For PA6/PP (80/20) blend compatibilized by 11 v% PP-g-MAH, the tensile strength at break attained 57.56 MPa and the Izod notched impact strength was 108.9 J m-1, increased by 8.87 MPa and 45.4 J m-1 respectively. Mechanism studies show that the improvement of microstructure and mechanical structure was caused by the formation of PP-PA6 copolymer through the reaction of reactive groups on PP-g-MAH and PA6.