Abstract: A process for coagulating a polybenzazole film which includes contacting a lyotropic polybenzazole dope film that is constrained in at least two directions with a coagulant under conditions such that the polybenzazole polymer separates as a gelled moiety with the structure set such that further removal of solvent will result in no more than a 5% increase in the force necessary to constrain the film.

Abstract: Films made from polybenzazole dopes can quickly be leached to remove polyphosphoric acid and other residual solvents by passing a leaching fluid such as steam through pores in the wet, never dried film. The process can reach acceptable residual phosphorous levels (1500-2000 ppm) in as little as about 2 or 3 minutes.

Abstract: Articles (other than fiber) made from polybenzazole dopes can quickly be washed to remove polyphosphoric acid by a combination of initially washing with an acidic liquid and second washing with a hot leaching fluid at at least about 60.degree. C. The process can reach acceptable residual phosphorous levels (1500-2000 ppm) in as little as about 2 or 3 minutes.

Abstract: Salts that contain AA-PBZ monomer ions and BB-PBZ monomer ions can be precipitated from an aqueous solution by contacting soluble salts of the monomers in an aqueous solution. The monomer salt can be polymerized by ordinary techniques to form polybenzazole polymers without the need for devolatilization and with very accurate stoichiometric control.

Abstract: PBZ polymers are synthesized by the reaction of AA- and BB-monomers. The BB-monomer is conveniently synthesized and isolated as a phosphate salt having a uniform number of phosphate ions associated with each BB-monomer ion. Such high purity monophosphate and diphosphate salts can be obtained by precipitating the monomer from an aqueous acid solution by adjusting the pH balance or from a mixture of phosphoric acid and a volatile, polar, saturated organic liquid at a relatively low temperature.

Abstract: An aminophenolic compound can be synthesized by contacting a halo-nitro-phenolic compound, such as 2-chloro-4,6-dinitrorescorcinol, with a hydrogenating agent, such as hydrogen, and a catalyst, such as palladium-on-carbon, in an aqueous solution in the presence of an acid such as phosphoric acid.

Abstract: Poly(vinylbenzyl ethers) of polyphenols are prepared by reacting an alkali metal, alkaline earth metal, or ammonium salt of a polyphenol with a vinylbenzyl halide in a liquid reaction medium consisting essentially or a monohydric alcohol or glycol having less than 12 carbons, a polyglycol having a weight average molecular weight ranging from about 200 to about 4000, or glycerol.Halide ion content of poly(vinylbenzyl ethers) of polyphenols prepared by the method of this invention and other methods are reduced by dissolving the ether in a solvent that dissolves no more than about 1.0 weight percent of an alkali metal, alkaline earth metal, or ammonium halide; separating the ether solution from the halide salt; and then recovering the ether from the solution.

Abstract: Monohalogenated cyclobutarenes are prepared by halogenating a cyclobutarene in the presence of an organic complexing agent, an acid scavenger, or water. Faster reaction rates highly selective to monohalogenated cyclobutarenes are obtained without conventional heavy metal or halogen catalysts.

Abstract: A 4-halomethyl-3,5-dihalo-2,6-dialkylphenol is hydrolyzed by contact with water to form a 4-hydroxy-methyl-3,5-dihalo-2,6-dialkylphenol under conditions to minimize formation of the corresponding bis-(4-hydroxy-3,5-dialkyl-2,6-dihalobenzyl) ether.

Abstract: Monobrominated cyclobutarenes are prepared by brominating a cyclobutarene in the presence of an organic complexing agent, an acid scavenger, or water. Faster reaction rates highly selective to monobrominated cyclobutarenes are obtained without conventional heavy metal or halogen catalysts.

Abstract: A method of producing a halogenated trialkyl phosphate ester which comprises admixing a halogenated hydroxy compound containing a halogen selected from the group consisting of bromine, chlorine, iodine and mixtures thereof, a phosphorus oxyhalide containing a halogen selected from the group consisting of bromine, chlorine, iodine and mixtures thereof, a solvent suitable to dissolve the halogenated hydroxy compound and the phosphorus oxyhalide, said solvent being substantially inert to hydrogen halide, and a catalyst suitable to increase the polarity of the phosphorus oxyhalide, refluxing said admixture sufficiently to form a trialkyl phosphate ester precipitate, and recovering this precipitate.

Abstract: Strong acid electrolytes are useful to acetoxylate substituted ethylbenzenes in acetic acid to substituted .alpha.-acetoxyethylbenzenes which can be converted to substituted vinylbenzenes.