Preparation and properties of <i>in-situ</i> reactive compatibilized ABS/PC blends with the aid of polypropylene

In the paper, in-situ reactive compatibilized acrylonitrile-butadiene-styrene/polycarbonate (ABS/PC) blends (70/30, g/g) were prepared by incorporating varying amounts of maleic anhydride (MAH) and dicumyl peroxide (DCP) during the melt blending process, and 2 wt% polypropylene (PP) was added to enhance the grafting efficiency of MAH, the products were then systematically characterized. Acid-base titration results indicated that the addition of PP enhanced both the grafting rate and conversion rate of MAH, which reached their maximum values at an MAH loading of 0.9 wt%. DSC analysis indicated that the primary graft copolymer formed during melt blending was PP-grafted MAH. The reduction in the glass transition temperature difference between ABS and PC indicated improved compatibility between the two polymers. DMA results showed that the interfacial adhesion between the ABS and PC phases was improved. SEM results showed that with the increase of MAH dosage, the PC phase changed from a flat shape to a spherical shape, and the average phase width significantly reduced from 12 μm to 4 μm. Mechanical tests showed MAH dosage tuned ABS/PC blends’ mechanical properties: tensile strength peaked at 0.9 wt% MAH, impact strength first drop then rose, due to dynamic competition between PP’s third-phase and PP-g-MAH’s interfacial enhancement effects. TG analysis indicated that the thermal stability of the compatibilized ABS/PC blends were nearly identical to that of pure PC/ABS blend. In summary, by leveraging the easy grafting property of PP, the prepared ABS/PC blends exhibit high compatibility, along with good tensile strength and toughness.