Characterization of organometallic polymers by chromatographic methods and nuclear magnetic resonance

Abstract

Organometal 1 ic polymers (OMP) are an increasingly important class of marine surface anti fouling agents undergoing intensive development by the U.S. Navy.Commercial procurement of such polymers, expected in the near future, will require Mil Specs designed to assure reproducibility between batches in order to achieve satisfactory reliability in service.New analytical methods are needed in writing such Mil Specs. Candidate OMP's have been characterizedat NBS by size exclusion chromatography (SEC) coupled with tin-specific graphite furnace atomic absorption spectroscopy (GFAA) as well as by Fourier transform nuclear magnetic resonance (FT-NMR).The key molecular parameters of many OMP's, the kinetics of formation of a typical copolymer, and the effects of different concentrations of free radical initiators on the formation of a copolymer in a well-stirred reaction system have all been characterized by 119 means of SEC-GFAA chromatograms.FT-NMR spectra of Sn have given kinetic information in good agreement with that obtained by SEC-GFAA. Both chemical shift and linewidth of the tin NMR signal have been shown to have an unusually large solvent and temperature dependence.Directions for future research on OMP's are discussed.