Solid-State Self-Assembly in Plasticized PVC/ABS Blends: Effects on Impact Strength and Dynamic Mechanical Properties

In this study, plasticized poly(vinyl chloride)/acrylonitrile–butadiene–styrene (PVC/ABS) blend was prepared via melt mixing. The morphological evolution and its effects on the blend’s properties were investigated over time. Scanning electron microscopy (SEM) analysis revealed the formation of rod-like supramolecular structures, suggesting the self-assembly in the blend. The simultaneous effects of physical aging, molecular-level interactions in the grafted SAN shell, and plasticizer-induced mobility are critical for the development of the unique microstructures in this system. The size and number of the structures were influenced by the plasticizer content, increasing with time and temperature. The impact strength increased due to the formation of these structures, and for the PVC/ABS-75/25 blend, it increased from 19 to 44.5 kJ/m². Dynamic mechanical analysis (DMA) revealed partial miscibility in the blend. The glass transition temperature (T_g) of PB-g-SAN in ABS was slightly increased over time due to the formation of rod-like structures.