Evolution of chemical structure of polydichlorophosphazene in various solvents and ways to prolong its stability

- Effects of various solvents on stability of polydichlorophosphazene were presented.
- Structural behaviors of PDCP in various solvents were also demonstrated.
- All structures were characterized by various analyses to predict their mechanisms.
- Active P+ ions can lead to degradation, branching and cross-linking of PDCP.

Polyphosphazenes are an important class of polymers due to their structural flexibility, synthetic versatility and their wide range of properties. Among them, poly(dichlorophosphazene) (PDCP) is an essential intermediate from which most of the polyphosphazenes can be synthesized through nucleophilic substitution reaction. One of the main challenges in its synthetic procedure is to control the side reactions such as undesirable processes of polymer degradation, branching and cross-linking owing to instability of PDCP. In this paper, we have investigated the stability of PDCP and its structural behaviors by the influence of various solvents such as DMSO, DMF, DMAc. THF, DCM, PX, and etc. The polarity of the solvents affected the P+ ions of PDCP, water absorption capacity and its intermolecular interactions which are responsible for degradation and cross-linking of PDCP. The polymeric species and their mechanistic chemistry are characterized by multinuclear NMR, FT-IR and mass spectrometry to confirm their detail structures by changing the solvents.

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