02342nas a2200277   4500008004100000022001400041245015600055210006900211260000900280300001400289490000700303520134000310653005801650653002101708653002801729653002601757653001701783100001701800700002001817700001901837700001801856700001801874700003101892700002001923856012101943       2025                        eng d  a1060-132500aAn improved one-pot synthesis of polydichlorophosphazene from ammonium sulfate and phosphorus pentachloride and assessment of its stability in solution0 aimproved onepot synthesis of polydichlorophosphazene from ammoni  cNOV   a1016-10260 v623 a<p>
	Polyphosphazenes, with their synthetic flexibilities, can be tailored to achieve various desirable properties. The synthesis of basic linear polymer polydichlorophosphazene (PDCP) free of branching and crosslinking is the most challenging step, and its extreme sensitivity to moisture makes storage and handling difficult. In the reaction of (NH4)2SO4and PCl5 (1:4.5 mole ratio) via one-pot two-step method, the monomer [Cl3PNP(O)Cl2] synthesized from the 1st step directly undergoes bulk polycondensation (2nd step) to produce PDCP. Due to impurities, the produced PDCP is afflicted by frequent branching, cyclic oligomers, and crosslinking. We are reporting an improved one-pot synthesis coupled with an in-situ purification step of the monomer (as confirmed by 31P NMR) with little excess PCl5 in mole ratio (1:4.6-1:4.8). Further, the stability of PDCP and its solutions in toluene and THF have been examined under an inert atmosphere at three different temperatures: room temperature, 0 degrees C-4 degrees C, and -25 degrees C. These stored samples were monitored for cross-linking, gelling, or any other degradation by characterizing through 31P NMR for the appearance of additional peaks. The PDCP can be stored at -25 degrees C for 2 months (pure) and 4 months (toluene) without any deterioration in its structure.</p>
10aP-trichloro-N-(dichloromonophosphoryl)monophosphazene10aPolycondensation10aPolydichlorophosphazene10astability in solution10astorage life1 aYadav, Abhay1 aYadav, Prashant1 aNewale, S., P.1 aSrivastav, V.1 aSingh, A., P.1 aShanmuganathan, Kadhiravan1 aSikder, Nirmala  uhttp://library.ncl.res.in/content/improved-one-pot-synthesis-polydichlorophosphazene-ammonium-sulfate-and-phosphorus