Ticona Gmbh

Celanese Sales Germany Gmbh

Stanley Leonard

Damian Feord

Michael Haubs

Hendrich A Chiong

Venkata Nekkanti

Jacob Grayson

Hanno Hueckstaedt

Matthias Göring

Joni Sianturi

A process for producing a cyclic acetal is disclosed. According to the process, a formaldehyde source is combined with an aprotic compound and contacted with a heterogeneous catalyst which causes the formaldehyde source to convert into a cyclic acetal such as trioxane. The catalyst, for instance, may comprise a solid catalyst such as an ion exchange resin. In one embodiment, the process is used for converting anhydrous formaldehyde gas to trioxane. The anhydrous formaldehyde gas may be produced form an aqueous formaldehyde solution by an extractive distillation. The aprotic compound and the formaldehyde solution may be extracted from the reaction product and recycled into the process.

Process for producing a cyclic acetal in a heterogeneous reaction system

A method for formation of a semi-crystalline polyarylene sulfide is described. The method can include reaction of sulfur-containing monomer with a dihaloaromatic monomer in an organic amide solvent to form a polymer following by combination of the polymer with a crystallization solution. The crystallization solution is pre-heated and the mixture formed is slowly cooled to crystallize the polymer.

Method of polyarylene sulfide crystallization

A multi-stage process and system for formation of a polyarylene sulfide is described. The multi-stage process can include at least three separate formation stages that can take place in three different reactors. The first stage of the formation process can include reaction of an alkali metal sulfide with an organic amide solvent to form a complex including a hydrolysis product of the solvent and an alkali metal hydrogen sulfide. The second stage of the formation process can include reaction of the complex formed in the first stage with a dihaloaromatic monomer to form a prepolymer, and the third stage can include further polymerization of the prepolymer with additional monomers to form the final product.

Multi-stage process for forming polyarylene sulfides

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Corpus Christi, TX, United States of America

Stanley Leonard