Plane-stress fracture toughness of hygrothermally degraded PC/ABS blends evaluated by the essential work of fracture: characterization and degradation-index-informed prediction

PC/ABS blends are widely used in thin-walled components for electronics and automotive applications, where resistance to hygrothermal embrittlement is important for long-term durability. In this study, the degradation of fracture resistance under plane-stress conditions was investigated for two PC/ABS blends (50:50 and 75:25) using double-edge-notched tensile (DDENT) specimens and the essential work of fracture (EWF) methodology. The specimens were subjected to accelerated hygrothermal aging at 85 °C/85% RH for up to 1344 h. The specific essential work of fracture, w e , and the slope term, βw p , were used to quantify intrinsic fracture resistance and crack-growth-related plastic dissipation, respectively. Both parameters decreased with increasing exposure time for both blends. The 50:50 blend exhibited marked deterioration and a transition to brittle behavior after 1008 h, whereas the 75:25 blend showed a similar transition after 672 h, indicating earlier embrittlement. In addition, statistical analyses were performed to further assess the degradation-related property reductions, and a data-informed property prediction model was developed by training an artificial neural network using FT-IR-derived chemical indices and data augmentation. The predicted EWF parameters showed close agreement with the measured values, supporting the proposed data-informed framework for durability assessment of thin-walled PC/ABS structures under hygrothermal environments.