N_w= 1+p/1-p

p = Extent of reaction

The question is related to step growth Polymerisation. Nw Refers to Chain length based on Weight.

Please don't attempt if you are planning to answer Mw and Mn followed by PDI. Please don't waste my money.

Taylor carefully fractionated a sample of nylon-6.6 and determined the weight fraction of different i-mers in the resulting mixture (G. B. Taylor, J. Am. Chem. Soc. 69, 638 (1947)). The results obtained are given below. Evaluate Ny from these data, then use eq 2.4.9 to calculate the corresponding value of p. Calculate the theoretical weight fraction of i-mers using this value of p and a suitable array of i values. Plot your theoretical curve and the above data points on the same graph. Criticize or defend the following proposition: although the fit of the data points is acceptable with this value of p, it appears that a slightly smaller value of p would give an even better fit. 134 Chapter Two, Step-growth polymerization, Version of 1/5/05 i W; X 10-4 i W; X 10-4 12 6.5 311 15.2 35 19.6 14.1 334 357 58 29.4 13.0 81 33.0 380 11.5 104 35.4 403 11.0 9.1 127 36.5 426 150 33.0 449 7.2 173 472 6.5 196 27.6 25.2 22.9 4.9 495 518 219 4.3 242 19.4 541 3.9 265 18.5 564 3.3 288 16.8