| 摘要 |
Polymerization grade phosphonitrilic chloride trimer is made by reacting NH4Cl and PCl5 in a solvent (e.g. monochlorobenzene) to form a crude trimer solution, filtering the solution to remove unreacted NH4Cl, distilling a portion of the solvent to form a hot concentrate, cooling the concentrate to obtain a precipitate, distilling the precipitate at reduced pressure to first remove a forecut and then a heart-cut of polymerization grade phosphonitrilic chloride trimer.
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