Langley Plot

The corresponding plot of G/T versus v RTfT is called the Langley plot and has been widely used Experimental points representing imperfect networks of the same initial functionality of the crosslinldng agent Imt differsit molecular weights... 

Figure 4. Langley-Graessley plot for networks with 0 > 10.

Figure 6. Langley-Graessley plots for networks formed and tested in bulk. Conditions , formed and tested in solution, 1.10 slope formed in solution, tested in extracted, deswollen state, 1.14 slope A. [o = 43.9L] 1.11 slope.

The plot Ge/Te vs. vg/Te yields then A from the slope and from the intercept (Langley-Greassley plot). The applicability of this plot will be commented on below and it will be shown that this plot is not very suitable for endlinked networks with varying as a function of the conversion or molar ratio of components. The similarity between the shapes of v e and Te and the resulting relative constancy of /Tg is the reason. The other disadvantage of analysis of experimental data using Eq.(1) or (5) based on the difference between the values Ge and Ve is the sen-... 

Fig. 7.1. Plot of modulus data on poly(dimethyl siloxane) networks to determine g and Me by Langley s method [Eq.(7.26)] (292)...

FIG. 14-6. Calculated contributions of cross-link strands and trapped entanglement strands to total number of effective strands in moles/m plotted against concentration of cross-linked units, for poly-(di.methyl siloxane) with M = 0.5 X 10 and = I.O X 10 from equation 6. (Langley and Pol-manteer. ) Reproduced by permission, from The Journal of Polymer Science ... 

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