29 How Does The Average Polymer Concentration Inside An Individual Coil Vary With M In Good And Theta Solvents Estimat 1 (71.66 KiB) Viewed 43 times
for problem 6.18 reference:
29 How Does The Average Polymer Concentration Inside An Individual Coil Vary With M In Good And Theta Solvents Estimat 2 (14.13 KiB) Viewed 43 times
29. How does the average polymer concentration inside an individual coil vary with M in good and theta solvents? Estimate this concentration in g/cm for polystyrene with M= 10% under both conditions, using Miyake et al.'s data given in Problem 6.18. Consider a melt of monodisperse polystyrene chains, and recall that in the melt the conformations are Gaussian. a. For degrees of polymerization N between 10 and 10,000, calculate the volume pervaded by an individual chain, Vp, assuming almost all the monomers are contained somewhere in a spherical volume with radius R. b. Calculate the concentration of a single chain within V, in g cm, and prepare a double logarithmic plot of this quantity against N. What is the asymptotic slope? c. Calculate the number of other chains, n, that must fill the rest of Vp, and prepare a double logarithmic plot against N. What is the asymptotic slope? d. If we have a face-centered cubic packing of hard spheres, and we increase the molecu- lar weight of all the spheres, how does the number of nearest neighbors vary? Why is the answer different from (c)?
M. x 10-6 R. (nm), Benzene R. (nm), Benzene Re (nm), Cyclohexane . 56.2+1 506 + 10 228 +5 39.5+1 3928 1834 32.0+0.6 353 +7 167+4 23.5+0.5 2979 1453 15.1 +0.5 227 +7 116+2 8.77 +0.3 1644 87.942
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