Solvent replacement in the synthesis of persubstituted phosphonitrilic hydroquinone prepolymer materials

Abstract

A desirable solvent replacement has been effected in the synthesis of persubstituted phosphonitriiic hydroquinone prepolymer materials. The replacement of carbon tetrachloride with cyclohexane has no adverse effect on the composition and quality of the material prepared. The overall yield of the reaction increases from 65 to 70% and the toxicity of the reaction mixture and of the waste generated from the reaction are greatly reduced. The particularly close match of solvent properties between carbon tetrachloride and cyclohexane makes this an excellent solvent replacement. Such changes to less-expensive, iess-toxic, and less-environmentally damaging solvents are on the increase. A brief list of some known replacement sofvents for use in polymer and coatings applications is presented. With a growing awareness of the health and environmental hazards of many common solvents, much time and effort has been expended in the search for suitable replacements. The budgetary impact of pertinent regulatory statutes has provided some of the driving force behind such efforts. This impact is felt by both industrial and educational laboratories. Consequently, industry and academia are formulating a number of useful replacement solvents and solvent mixtures. Proposed replacements are often judged on their ability to perform the pertinent function, yet they may have very different physical and chemical properties as compared to the solvent they are meant to replace. A search of the recent literature yields a number of replacements related to polymer and coatings applications: terpenes in place of halogenated solvents in cleaning applications,' toluene in place of carbon tetrachloride for preparing solutions of chlorosulfonated polyethyl-*

Reactions and polymerization of hexa-[3-tert-butyl-4- hydroxyphenoxy]cyclotriphosphazene: A new method for the preparation of soluble cyclomatrix phosphazene polymers

“…Syntheses of crosslinked 1 16 and neat cyclic trimer 2 17 have been reported to occur in a facile manner with high yields. Each of these cyclotriphosphazenes contains free aromatic hydroxyl groups that afford synthetic pathways to expand the chemistry of these systems.…”

Phosphazene cyclomatrix network polymers: Some aspects of the synthesis, characterization, and flame‐retardant mechanisms of polymer

“…Therefore, one active group of the bifunctional component must be protected first and then deprotected to form a distinct cyclic trimer, which complicates the reaction procedure and limits its applications. 14,15 Recently, a particularly interesting cyclomatrix system aimed at flame-retardant application was derived from reactions of phosphazene-ringcontaining maleamic acids, which resulted in highly crosslinked resins on heating and further thermal curing. The polymerization of the tris-p-aminophenoxytris-p-phenyl maleimide species gave a resin with 82% char at 800°C.…”

Phosphazene monomers from the regiospecific reaction oftert-butylhydroquinone with hexachlorocyclotriphosphazene: A new composite material precursor

“…An report 21 detailed the synthesis of hexahydroquinonecyclotriphosphazene prepolymer materials based upon an earlier patent. 22 The term prepolymer was employed because hydroquinone, a bifunctional organic nucleophile, has the capability of crosslinking phosphazene rings, and it was not clear to the authors the extent to which this occurs during the synthetic process.…”