Structure–Property Relationships in Polycarbonate Compatibilized Acrylonitrile Butadiene Styrene/Polyethylene Terephthalate Blends

ABSTRACT Polycarbonate (PC) was investigated as an in situ reactive compatibilizer for otherwise immiscible acrylonitrile‐butadiene‐styrene (ABS)/polyethylene terephthalate (PET) blends. Blends with a fixed ABS:PET weight ratio of 70:30 were prepared by melt blending, both in the absence and presence of PC at loadings of 5, 10, and 15 wt%. Scanning electron microscopy (SEM) revealed progressive refinement and stabilization of PET domains with increasing PC content, indicating enhanced interfacial interaction. Parallel‐plate rheology showed a noticeable increase in low‐frequency complex viscosity () and a systematic shift of the storage–loss modulus (G′–G″) crossover toward higher frequencies, reflecting suppression of slow interfacial relaxation and improved phase interaction. Fourier transform infrared spectroscopy (FTIR) confirmed the occurrence of transesterification reaction between PC and PET phases. Differential scanning calorimetry (DSC) demonstrated a reduction in PET crystallinity, attributed to restricted chain mobility arising from compatibilization. Correspondingly, the mechanical properties improved with increasing PC concentration, accompanied by a reduction in melt flow. Overall, the results confirm that PC functions as an effective reactive compatibilizer for ABS/PET blends, leading to enhancements in interfacial interaction, rheological behavior, and thermo‐mechanical performance.