Solid-State Polymerization Processes

The objective of this research is the development of new methods for the controlled synthesis of macromolecules. Specifically, attempts will be made to develop solid-state polymerization processes to yield polymers that cannot be synthesized by other methods. The work falls into four main topics. (1) Unsaturated organic monomer molecules will be clathrated in the molecular level tunnel systems formed by certain crystalline solids. The monomers will then be polymerized in the tunnels by exposure to high energy irradiation or by chemical initiation. Stereospecific polymerizations are expected in some cases. (2) Attempts will be made to prepare one-dimensional metallo-backbone polymers by the use of the same tunnel clathration technique. (3) Cyclic phosphazenes which crystallize in appropriate crystal packing arrangements will be polymerized by gamma-irradiation methods. It is expected that this route will generate polymers not accessible by the conventional thermal melt polymerization route. (4) Other cyclic inorganic systems that crystallize in suitable space groups will also be studied by gamma-irradiation methods. These systems include heteroelement phosphazenes, boron-nitrogen-, sulfur- nitrogen-, and other heterocyclic rings. Most of the systems to be studied have proved to be resistant to conventional thermal ring- opening polymerization methods. The polymers prepared in this work should have new macromolecular structures and new combinations of properties that are potentially useful in electronic, optical, magnetic, and other applications.