Polycarbonate molecular weight data

The viscosity data for several different molecular weight grades of commercial polycarbonate resin are shown in Figure 4. From this plot the relative processability of these materials can easily be determined by comparing their viscosities at the shear rates used in processing. 

For PEO, p 1.9 A [39]. Detailed information on the chain dimensions and density of TMPC is not available, but an estimate for p can be obtained from data for bisphenol A polycarbonate, which has p=1.55 A [39]. If the addition of four methyl groups is assumed to increase Vq by an amount that is proportional to the increase in molecular weight, while not affecting the statistical segment length, one obtains p= 1.9 A for TMPC, a value equal to that of PEO. 

Molecular Weight Distribution Data for Nylon 6, Polycarbonates, and Other Polymers ... 

A comparison of the data on the change in chemical properties and molecular weight of polycarbonate subjected to reprocessing under the conditions of various systems (Fig. 155) showed that the drop in strength is due to a decrease in the molecular weight of the polymer. 

Table 44 Decrease in the molecular weight of 7 Co-irradiated polycarbonate (dose rate 2 kGy.h ). The data were taken from [07D1].

Using these parameters for predicting the vapor-liquid equilibrium in the polycarbonate/chlorobenzene system kij = 0) at 140°C leads to results shown in Fig. 4. It is obvious that the results are very unsatisfactory a description of the experimental data also fails for any other value of the binary parameter Therefore, the polycarbonate parameters m (uncertain since the molecular weight for the density data was unknown) and s/k were refitted to the binary data in Fig. 5a. Using these new parameters m/M = 0.0080, e/A = 256.97 K and Vqo = 17.114 cm /mol, the experimental data can now be described very well. 

Soloukhin, V. A., Brokken-Zijp, J. C. M. et al. Physical Aging of Polycarbonate Elastic Modulus, Hardness, Creep, Endothermic Peak, Molecular Weight Distribution, and Infrared Data, Macromolecules, 36 (2003), p. 7585-7597... 

Striking effects of molecular weight on FCP rates in notched PMMA (89) and PVC (90) have been noted (91,92), and similar strong effects have been reported for polycarbonate (93) and polystyrene (94). In general, the Paris law is followed over a wide range of AK. It was found (94,95) that this data followed the following empirical relationship ... 

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