1964 Volume 37 Issue 12 Pages 1762-1768
In the preceding paper it was reported that the degree of the stereoregularity of polymethyl methacrylate could be determined from the NMR spectrum through the analysis of three peaks due to the α-methyl groups. It has been found that the infrared spectrum can also give an equivalent result if it is once calibrated by the NMR method.
We have considered a statistical method to interpret any locus in the ternary diagram which corresponds to the change in the stereoregularity of polymers with the polymerization temperature and with the type of catalyst. By introducing two parameters, the average sequence length of I-, D- and S-blocks have been calculated.
On the other hand, the acetone-extraction of the samples prepared in anionic polymerization has been carried out in order to determine the degree of stereoregularity of both the extract and the residue. From the plots in the ternary diagram, we have discussed some mechanisms of the anionic polymerization. We may conclude that two different mechanisms take place in the course of the ploymerization using an R2Mg catalyst in contrast with the polymerization catalyzed by RMgBr.
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