PMMA, maximum craze width

Fig. It a and b. Variation with crack speed of the dimensions of the craze zone at the tip of a propagating crack in PMMA a maximum craze width 2Vj b craze length s...

In the context of the results for moving cracks discussed in the previous section it should be noted that the craze sizes reported in this section have been measured from just after onset of slow crack propagation to speeds up to 10 " mm/s Quantitative results of maximum craze width as a function of temperature T are compiled in Fig. 15 for PMMA pc and PVC At a first glance there... 

In PMMA the effects of molecular weight and of molecular weight distribution on craze dimensions and on crack opening have been intensively studied In Fig. 17 the results of the maximum craze width are represented as function... 

Fig. 17. Maximum craze width 2V(. in PMMA of different molecular weight distributions as a function of molecular weight M at different temperatures...

Fig. 23a and b. Growth of a primary craze at a stationary crack tip in PMMA in air, K, = 19 N/mm a craze length s as a function of loading time t b maximum craze width 2v as a function of loading time t... 

Figure 3.22 shows the maximum craze width 2v and the corresponding craze length s as functions of crack speed a in HMW and LMW PMMA. The crack speeds for the HMW material cover the complete range of slow crack growth, while LMW PMMA has been investigated only up to speeds around 10 mm/s... 

Fig. 3.22a, b. Speed dependent variation of the craze dimensions at the tips of propagating cracks in PMMA of different molecular weights a craze kngth s and b maximum craze width 2v ... 

For 6 nm < a7 < 12 nm, Qc increases sharply with interfacial width, suggesting a transition from failure by simple fracture or pullout, to failure after formation of a craze at the crack tip. This craze is clearly observable in the PS-PMMA studies. Once the transition is passed, the increase in Qc is due to the increase in the maximum stress that can be sustained by the fibrils since all polymers in this study have very similar crazing stresses. 

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