Environmental stress cracking prediction

Hansen CM, Just L (2001) Prediction of environmental stress cracking in plastics with Hansen solubility parameters. Ind Eng Chem Res 40( 1) 21—25... 

Hansen CM (2002) On predicting environmental stress cracking in polymers. Polym Degradat Stabil 77(l) 43-53... 

Jacques CHM, Wyzgoski MG (1979) Prediction of environmental stress cracking of polycarbonate from solubility considerations. J Appl Polym Sci 23(4) 1153—1166... 

Hansen, C.M. and Just, L. (2001) Prediction of Environmental Stress Cracking in Plastics with Hansen Solubility Parameters, Ind. Eng. Chem. Res. 40,21-25. 

Polypropylene may be subject to environmental stress cracking (see Chapter 1). The occurrence is difficult to predict. It is dependent upon the process chemistry, operating conditions, and quality of fabrication. In table 3.9, which gives the compatibility of polypropylene with selected corrodents, certain chemical/liner ratings are identified by an e, indicating that the liner in contact with that specific chemical may be susceptible to ESC. Reference 2 provides a more comprehensive compatibility listing. 

The failure of plastics in chemical environments may occur through dissolving, swelling, environmental stress cracking (ESC) or actual chemical attack. Dissolving, swelling or ESC can be predicted by consideration of the materials solubility parameters but there are always limitations to this approach. The chemical resistance of PAEK... 

Prediction of environmental stress cracking of polycarbonate firom solubility considerations J. Appl. Pol. Sci. 23.1153 (1979)... 

Three examples of ESC of amorphous polymers include polystyrene with white spirit, polycarbonate with methanol and polysulfone with ethyl acetate. Susceptibility to environmental stress cracking is not predictable, thus requiring end-use testing of a polymer prior to finalizing part designs. 

Environmental stress cracking in polycarbonate -Prediction of the long term behavior by the use of short time tests... 

ENVIRONMENTAL STRESS CRACKING IN POLYCARBONATE - PREDICTION OF THE LONG TERM... 

This unsatisfactory situation is offset, however, by the increase in mechanistic understanding of environmentally assisted cracking, which has accelerated in the last decade because of the availability of experimental and analytical procedures that allow quantification and validation of various cracking hypotheses. The ultimate validation of any such mechanistically based model is its ability to predict the extent of crack penetration as a function of the wide combination of the material, stress, and environment factors relevant to LWR operation (Fig. 1). 

All the above modes of fracture are affected by the environment around the crack tip. This behaviour is typified by the phenomenon of stress-corrosion cracking where a crack, which is subjected to a subcritical stress concentration, will grow in a corrosive environment when /f, the critical stress concentration for stress-corrosion cracking). Therefore, to predict accurately the occurrence of cracking and crack growth rate, not only the materials properties are required but also information on the immediate environmental conditions. 

Moreover, lack of understanding of processing and heat-to-heat variations or the effects of trace alloying elements further limits the predictability of the onset or growth of stress corrosion cracks. Similar considerations can apply to environmental effects on high-temperature crack growth in gaseous environments. 

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