On the characterization of stereoregular polymers. III. Polymethyl methacrylate

The tacticity theory previously reported was generalized so it could be applied to the proton magnetic resonance data obtained for a variety of methyl methacrylate polymers. This system is the only one known for which sufficient data exist or may be obtained to provide a test of the theory. From the data available, parameters characterizing the distribution of iso‐ and syndiotactic sequence lengths in each sample were obtained These parameters, in turn, were used to predict melting behavior for each sample capable of crystallization. The tacticity theory not only is consistent with the data on free radical‐initiated (syndiotactic) polymers, about which there was no question of interpretation, it also provides an explanation for an uncertainty in the interpretation of the data on anionic‐initiated (isotactic) polymers. Thus, in this case at least, the theory appears to provide a connection between experimentation and polymer configuration.