Synthesis, characterization, thermal degradation, and comparative chain dynamics studies of weak-link polysulfide polymers

Synthesis, spectroscopic and thermal characterization of two new classes of polysulfide polymers: poly[1-(phenoxymethyl) ethylene polysulfide] (PPMEP), and poly[1-(phenoxy) ethylene polysulfide] (PPEP) is presented. The direct pyrolysis mass spectrometry (DP-MS) technique, used to study the thermal degradation behavior of these polysulfide polymers, indicated that the polymers underwent degradation through the weak-links scission. The thermal stability of the polysulfide polymers decreased as the “rank” (number of sulfur atoms in the polysulfide linkage; n = 1, 2, 4) increased. The main-chain flexibility of these polysulfide polymers in terms of their ¹³C NMR spin-lattice relaxation time (T ₁ ) measurements on the backbone methine (-CH-) and methylene (-CH₂-) carbons are reported here for the first time. A comparative study of the solution chain dynamics indicated that it increased as “rank” of the polysulfide linkages decreased as well as by introducing side chain spacers such as, ether (-O-) or methyleneoxy (-CH₂O-) groups.