When alcohol solution adheres to the amorphous polymer under loading, the crazing occurs even at loads below the allowable strength of the material and eventually leads to the rupture. Since unexpected deterioration and rupture due to alcohol adhesion significantly affect the reliability of plastic products, there is a need to ensure safety by predicting the product life made of plastic materials. This research aims to elucidate the progress of crazing due to the adhesion of alcohol to plastic materials by using the image analysis with the fractal dimension. A quarter-elliptical fixture method was applied to PMMA specimens under 0.5% and 0.8% strain with In-situ observation of the microscope. The experimental results revealed that the observation of the number and area of the crazing was insufficient because of the combination of the multiple crazing as time passed. Therefore, we proposed the image analysis with fractal dimension to quantitatively evaluate the complexity of the crazing with time dependence. The number of crazing units just before fracture was 207 at 0.5% strain and 173 at 0.8% strain, and the percentage of the area occupied by crazing was 19% at 0.5% strain and 22% at 0.8% strain. On the other hand, the fractal dimension converged to 1.55 for both strains, and the fractal dimension can be judged to be at risk of fracture when it reached 1.5. We believed that the fractal dimension was useful to predict the fracture of plastic materials under loading with alcohol adhesion.
