The kinetics of the polymerization of sarcosine carbonic anhydride

The polymerization of carbonic anhydrides, a reaction important but>u as a preparative method for the synthesis of polypeptides and as an example of a less familiar type of polymerization, has been studied in detail using sarcosine carbonic anhydride (I). The propagation reaction has been shown to involve a reversibly formed compound between the carbonic anhydride and the polymer; this compound decomposes by both a unimolecular and a bimolecular route. The equilibrium constant for the formation of the intermediate compound, and both velocity constants for its decomposition have been determined in two solvents, and the energies of activation and frequency factors calculated. The molecular weight distribution has been calculated; it is extremely sharp. The viscosities of the polymers prepared by this reaction have been measured, and the relation between the intrinsic viscosity and the molecular weight established.