One-step synthesis of mixed-substituted fluorinated cyclotriphosphazene compound and its thermal stability study
A one-step synthesis of mixed-substituted fluorinated cyclotriphosphazene compound was achieved using hexachloro-cyclotriphosphazene as a substrate and octafluoropentanol and 3-methylphenol as nucleophilic reagents.This approach,compared to traditional stepwise methods,involves simultaneous addition of all nucleophilic reagents to the reaction system.Control of nucleophilic reagent concentration and reaction time allows for the regulation of product structure,resulting in reduced reaction time and steps.For comparison,two cyclotriphosphazene compounds with full substitution,using octafluoropentanol and meta-methylphenol,were also synthesized.Characterizations of product structures through FT-IR and 31P NMR reveal that the one-step method produces compounds with 49%octafluoropentoxy and 51%phenoxy groups,while the stepwise method yields products with 34%octafluoropentoxy and 66%phenoxy groups.Additionally,the one-step method produces cyclotriphosphazene products with higher molecular weight side chains,as evidenced by Mn values of 1 356 compared to 1 230 for the stepwise method.TG results reveal that the temperatures at which the one-step and stepwise method samples experience 50%weight loss under N2 atmosphere are 333 and 365℃,respectively.The increased thermal stability is closely related to the higher proportion of phenoxy groups in the molecular structure.
NETL
NSTL
万方数据
