Thermal Functional Polymeric “Iniferters” Based on Phosphorus-Containing Poly(Thiuram Disulfides); Synthesis and Characterization

Abstract
Secondary amine end-terminated oligomeric poly(phosphonamides) and poly(phosphorylamides) were synthesized by the condensation reaction of phenylphosphonic dichloride, ethyl dichlorophosphate, 2,2,2-tribromoethyl dichlorophosphate, and 2,2,2-trichloroethyl dichlorophosphate with an excess of piperazine or N,N′-dimethyl-1,6-hexanediamine. The macrodiamines were chain extended by reaction with CS2 to the macrobis(dithiocarbamates) followed by oxidative coupling to the corresponding poly(thiuram disulfides) bearing the phosphorus functions. The diamine precursors and their polythiuram disuffides were characterized by elemental analysis, spectral analysis, thermal analysis, and viscosity measurements. The thermal stabilities of the prepolymers were correlated with their structures. The composition of the thiuram disulfide functions could be determined by TGA, whereas the kinetics of their thermal decomposition in the solid state was studied by DSC analysis. The activation energy varied with the chemical structure of the backbone but was quite independent of the chain length. Alternatively, oligomeric polythiuram disulfides containing phenyl phosphonate groups were synthesized by the condensation reaction of phenylphosphonic dichloride with N,N′-diethyl-N,N′-bis(2-hydroxyethyl)thiuram disulfide.