Dissolution driven crack branching in polycarbonate

Abstract

A B S T R A C T Stress corrosion, in the form of chemically assisted crack growth, in polycarbonate is examined with focus on crack branching characteristics. Cracks with finite width are observed; this is to be expected for dissolution driven cracking. The cracks branched repeatedly and crack widths before and after branching are measured. Both symmetric and asymmetric branching is found. The dissolution rate is assumed to be a linear function of the strain along the crack surface. In the literature, it is proposed that the crack width is proportional to the square of the mode I stress intensity factor. Energy considerations lead to that the sum of branch widths must equal the width of the unbranched crack. The results from this study correspond fairly well with this assumption. The branching angle is found to be 32 • ± 12 • , which is in line with results for sharp cracks reported in the literature. The mean growth direction of the branches is found to deviate slightly from the expected straight. No significant correlation between angles and crack widths is found. The scatter in results is mainly addressed to the inherent perturbation sensitivity of stress corrosion cracking. Also numerically simulations of crack branching is performed. These results show promising agreement with the experiments.

Unveiling the Role of CeO2 Atomic Layer Deposition Coatings on LiMn2O4 Cathode Materials: An Experimental and Theoretical Study

“…It has been established that, in stress corrosion cracking, when an uncovered metal surface was exposed to a hostile environment, loss of dissolved metal ions led to the formation of gaps and cracks . With a continuous cycle of material dissolution, crack propagation was promoted further. , In LIBs, the presence of corrosive hydrofluoric acid (HF) in the electrolyte accelerated the dissolution and led to a significant loss of capacity upon cycling. , A common approach to suppressing HF content was the application of protective coatings of binary oxides on cathode particles. Double-shelled LiMn 2 O 4 @LiNi 0.5 Mn 1.5 O 4 combined with an interior void can effectively suppress the Mn ion dissolution at the surface and shows unique rate capability and cycling stability .…”

“…57 With a continuous cycle of material dissolution, crack propagation was promoted further. 58,59 In LIBs, the presence of corrosive hydrofluoric acid (HF) in the electrolyte accelerated the dissolution and led to a significant loss of capacity upon cycling. 60,61 A common approach to suppressing HF content was the application of protective coatings of binary oxides on cathode particles.…”

Susceptibility to Stress Corrosion Cracking of Selected Amorphous Polymer Materials in a Sea-Water Environment

“…Research was carried out on thermoplastics and polymer composites based on resins [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. To name several examples, SCC can be observed when exposing polyethylene to aqueous detergents or organic solvents [24], high impact polystyrene to sunflower oil [25], the stress cracking behavior of injection moulded PET was investigated using sodium hydroxide (NaOH) aqueous solutions in various concentrations as active fluids [26], polycarbonate to ethanol or fat emulsions [27].…”