Molecular Weight Distribution of a Novel Condensation Polymerization. Comparison with Theory

The polymerization of divinylbenzene and p-cresol has been followed by gel permeation chromatography. The production of low molecular weight oligomers in the early stages of the reaction is characteristic of a typical condensation polymerization. An analysis of the relative amounts of p-cresol, dimer, and trimer, however, shows that the molecular weight distribution is not that of the “most probable” distribution. In addition, evidence from GC/MS suggests that all functional groups are not equally reactive. These findings are discussed in terms of a theoretical treatment of nonrandom polymerization. Incorporating the assumption that each ortho site on p-cresol is between two and four times as reactive as that on monosubstituted cresol provides a calculated distribution in better agreement with the data. A modified extent of reaction parameter, p*, is suggested for direct comparison of theory and experiment.