Abstract: Methods of forming a polyarylene sulfide and systems as may be utilized in carrying out the methods are described. Included in the formation method is a filtration process for treatment of a mixture, the mixture including a polyarylene sulfide, a salt byproduct of the polyarylene sulfide formation reaction, and a solvent. The filtration process includes maintaining the downstream side of the filter medium at an increased pressure. The downstream pressure can such that the boiling temperature of the mixture at the downstream pressure can be higher than the temperature at which the polyarylene sulfide is insoluble in the solvent.

Abstract: 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.

Abstract: The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) formaldehyde source, b) an aprotic compound and c) a catalyst; and ii) converting the formaldehyde source into cyclic acetals.

Abstract: Methods, devices, and systems that can be utilized in separating a polymer from other compounds of a polymer formation process are described. The methods utilize multiple sedimentors in a countercurrent flow design in conjunction with different solvent solutions in the multiple sedimentors to separate a product polymer from other compounds of a polymer formation process. The sedimentors include feed inlets that can encourage contact between countercurrent flows and improve mass transfer rates between the countercurrent flows.

Abstract: 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.

Abstract: The present invention relates to a process for producing cyclic acetal comprising i) preparing a reaction mixture comprising a) a formaldehyde source in a liquid medium and b) a catalyst; ii) converting the formaldehyde source into cyclic acetals, wherein the final conversion of said formaldehyde source to said cyclic acetal is greater than 10% on basis of the initial formaldehyde source.

Abstract: The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) a formaldehyde source, b) an aprotic compound and c) a catalyst; wherein the total amount of protic compounds is less than 40 wt.-%, based on the total weight of the reaction mixture; and ii) converting the formaldehyde source into cyclic acetals.

Abstract: Methods of forming a polyarylene sulfide and systems as may be utilized in carrying out the methods are described. Included in the formation method is a filtration process for treatment of a mixture, the mixture including a polyarylene sulfide, a salt byproduct of the polyarylene sulfide formation reaction, and a solvent. The filtration process includes maintaining the downstream side of the filter medium at an increased pressure. The downstream pressure can such that the boiling temperature of the mixture at the downstream pressure can be higher than the temperature at which the polyarylene sulfide is insoluble in the solvent.

Abstract: 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.

Abstract: 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.

Abstract: A process for producing cyclic acetals is described. A formaldehyde source is contacted with an aprotic compound in the presence of a catalyst to produce the cyclic acetals. The aprotic compound can increase conversion rates and/or efficiency. In one embodiment, the formaldehyde source is obtained from methanol. In particular, methanol can be converted into formaldehyde which is then converted into a cyclic acetal. In one embodiment, the cyclic acetal can then be used to produce oxymethylene polymers.

Abstract: A process for recycling polyoxymethylene polymers is disclosed. A polyoxymethylene polymer is at least partially dissolved in an aprotic compound. The resulting solution or suspension (liquid mixture) is then contacted with a catalyst which causes the polyoxymethylene polymer to be converted into a cyclic acetal. The cyclic acetal can be separated, collected and used in other processes. In one embodiment, the cyclic acetal may be used to produce a polyoxymethylene polymer.

Abstract: The synthesis of nanoparticles based on hyperbranched-linear-hyperbranched ABA triblock copolymers with hyperbranched polyglycerol (hbPG) as A-block and linear poly(oxymethylene) as B-block is described. The acid-degradable nanoparticles were formed in a facile process, combining a solvent evaporation process with the miniemulsion technique resulting in particles with a diameter in the range of 190 to 250 nm and a standard deviation of ˜30% determined with DLS and SEM. The nanoparticles were placed on a silicon wafer and sintered leading to films with a thickness in the ?m-range investigated via SEM. The surface properties of these films were investigated via static contact angle measurements at the liquid/vapor interface. The contact angle decreases from 67° for the polymer with two hydroxyl groups to 29° for the polymer with 16 hydroxyl groups, confirming the influence of the polymer structure and size of the hbPG block on the surface properties.

Abstract: Methods of forming a polyarylene sulfide and systems as may be utilized in carrying out the methods are described. Included in the formation method is a filtration process for treatment of a mixture, the mixture including a polyarylene sulfide, a salt byproduct of the polyarylene sulfide formation reaction, and a solvent. The filtration process includes maintaining the downstream side of the filter medium at an increased pressure. The downstream pressure can such that the boiling temperature of the mixture at the downstream pressure can be higher than the temperature at which the polyarylene sulfide is insoluble in the solvent.

Abstract: 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.

Abstract: A water soluble polyoxymethylene copolymer is described. In one embodiment, the polyoxymethylene copolymer is a liquid at 35° C. and is water soluble. The polyoxymethylene copolymer may have a comonomer content of greater than about 60% by weight, such as greater than about 70% by weight, such as greater than about 80% by weight. The copolymer is usually formed using a chain transfer agent. The polyoxymethylene copolymer can be formed so as to have a relatively low molecular weight and have a relatively great amount of end groups or terminal groups. For instance, the copolymer may contain end groups in an amount greater than 300 mmol/kg.

Abstract: A process for recycling polyoxymethylene polymers is disclosed. A polyoxymethylene polymer is at least partially dissolved in an aprotic compound. The resulting solution or suspension (liquid mixture) is then contacted with a catalyst which causes the polyoxymethylene polymer to be converted into a cyclic acetal. The cyclic acetal can be separated, collected and used in other processes. In one embodiment, the cyclic acetal may be used to produce a polyoxymethylene polymer.

Abstract: An initiator for cationic polymerization comprises a salt of a protic acid as well as a protic add. The molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000. The initiator is used for example for cationic homo- or copolymerization of trioxane, and permits stable and flexible operation of the polymerization.

Abstract: Synthesis of hyperbranched-linear-hyperbranched ABA triblock copolymers based on linear poly(oxy methylene) (POM) and hyperbranched poly(glycerol) (hbPG) blocks is described. The polymers having a polyacetal polyether structure were prepared from linear bishydroxy functional POM macroinititators, obtained by cationic ring-opening polymerization of trioxane and dioxane with formic acid as transfer agent and following hydrolysis of the formiate group. Partial deprotonation of the resulting hydroxyl groups permitted the hypergrafting by anionic ring-opening multibranching polymerization (ROMBP) of glycidol.

Abstract: The present invention relates to a process for the preparation of oxymethylene polymers, the oxymethylene polymers obtained therefrom as well as their use.