Abstract: This process relates to controlling acetal formation when removing acetaldehyde from a methanol carbonylation process using an extractive distillation column. Acetals may be formed by a secondary reaction of acetaldehyde and an alcohol (such as methanol). The process controls the formations to prevent excess acetal accumulation in the lower stream from the extractive distillation column.

Abstract: A process for producing acetic acid is provided that is capable of lowering acetaldehyde mass composition in acetic acid. The process for producing acetic acid according to the present invention comprises at least one distillation step that satisfies the following operating conditions (i) temperature in a lower portion of the distillation column is not less than 40° C.; (ii) water mass composition in the lower stream is not less than 0.3 wt. %; or (iii) acetic acid mass composition in the lower stream on weight percentage basis is greater than the acetic acid mass composition in the first mixture; wherein the methanol mass composition in the first mixture is less than or equal to 2 wt. %.

Abstract: A process for producing acetic acid that involves operating the flash vessel and first column at the lowest possible pressure for a given production rate is described. Low pressures are achieved by operating on a back pressure established by a vapor discharge from an absorbing system. This reduces the pressure differential to allow steady and efficient acetic acid production.

Abstract: Methods of producing gold-palladium catalysts suitable for use in the production of vinyl acetate may include drying the catalyst after the incorporation of a promoter at higher temperatures (e.g., 160° C. or greater) to restructure the metals and/or alloys on the catalyst. The restructured catalyst advantageously has increased catalytic activity and improved stability.

Abstract: Ion chromatography may be used for measuring the concentration of metal ions in various streams of a vinyl acetate production process. For example, a method may comprise: reacting ethylene, oxygen, and acetic acid in the presence of a catalyst and optionally a catalyst promotor like sodium acetate and/or potassium acetate to yield a crude vinyl acetate stream; measuring a concentration of a metal ion of the crude vinyl acetate stream and/or a stream downstream thereof with an ion chromatograph, wherein the metal ion is selected from the group consisting of Group I metal ions, Group II metal ions, transition metal ions, and any combination thereof.

Abstract: A colorized and tribologically modified polyoxymethylene polymer composition is disclosed. The polyoxymethylene polymer composition is comprised of a polyoxymethylene polymer in combination with at least one tribological modifier. The tribological modifier may include a fluoropolymer. The polymer composition further contains at least one coloring agent in combination with a color stabilizer. The color stabilizer has been found to dramatically improve color consistency. Polymer articles molded from the polymer composition not only have excellent surface appearance but have excellent low friction characteristics when tested against aluminum.

Abstract: Continuous acetic acid production with a process to remove and/or reduce permanganate reducing compounds (PRCs), including acetaldehyde. The process involves obtaining a stream comprising the PRCs and removing water from the stream through a dehydrating step, involving distillation, extraction, or phase separation. After removing water, an alkane may be combined to enhance the separation of PRCs from alkyl iodides.

Abstract: A biocide- and ammonia-free aqueous polymer dispersion is obtained by radically initiated multi-stage emulsion polymerization and comprising particles comprising at least a first polymer phase formed from a monomer composition I and a second polymer phase from a different monomer composition II. The first polymer phase has a glass transition temperature below 20° C., and the second polymer phase has a glass transition temperature above 20° C., both as determined by differential scanning calorimetry according to ISO 16805. The polymer dispersion further comprises at least one water-soluble alkali metal silicate, at least one water-soluble alkali metal or alkaline earth metal alkyl siliconate, or a mixture thereof and has a pH of 10.0 or higher.

Abstract: Coating compositions are useful for applying to surfaces of molding, include concrete moldings such as roofing tile. The coating composition comprise monomers that provide advantageous properties to reduce water uptake as well as improving the aesthetic appearance.

Abstract: Methods and systems for producing vinyl acetate may use flammability limit (FL) formulas with improved efficiencies at more than one location in the vinyl acetate production process. Herein, FLs can be used at one or more of four portions of the vinyl acetate production process: the reactor, the process-to-process heat exchangers, the carbon dioxide removal system, and the ethylene recovery system. Such FLs are functions of operating conditions and include at least one interaction term that represents the interrelation of two or more of the operating conditions (e.g., temperature, pressure, and component concentration) on the FL.

Abstract: A method for catalytic vapor phase oxidation of methanol to formaldehyde may include: passing a feed stream comprising methanol and oxygen through a layered catalyst bed having a first layer comprising a first silver catalyst particles and a second layer comprising a second silver catalyst particles that are different than the first silver catalyst particles, wherein the feed stream passes through the first layer before the second layer, wherein the first silver catalyst particles has a greater reaction activity for converting methanol and oxygen to formaldehyde; and reacting the methanol and the oxygen in the presence of the catalysts to produce a product stream comprising formaldehyde.

Abstract: A thermoplastic vulcanizate composition, comprising a first phase bi-continuously intertwined with from about 10 wt % to 80 wt % of a second phase throughout the composition, and from about 0.1 wt % to about 10 wt % of a curative system, the first phase comprising polypropylene and the second phase comprising an at least partially cured elastomeric rubber composition, comprising from about 10 wt % to about 40 wt % ethylene, from about 5 wt % to about 10 wt % of a conjugated diene having from 4 to 12 carbon atoms, and from about 50 wt % to about 85 wt % of a C4-C8 alpha olefin, based on the total weight of the elastomeric rubber composition present. A process for making is also disclosed.

Abstract: The present disclosure relates to TPV compositions suitable for foaming, as well as foamed TPV compositions, methods of making the foregoing, and applications of various foamed TPV compositions, including in glass run channels. The TPV compositions comprise an at least partially vulcanized rubber component dispersed within a thermoplastic component comprising a first thermoplastic resin. According to some aspects, the TPV composition may be combined with a high melt-strength thermoplastic resin, and in particular a high melt-strength polypropylene-based thermoplastic resin, to make a foamable TPV composition. The foamable TPV composition (with or without high melt-strength thermoplastic resin) is then coextruded or otherwise combined with foaming agent (preferably comprising thermo-expandable microspheres) to form the foamed composition.

Abstract: A multistage emulsion polymerization process comprises polymerizing a first monomer composition comprising from 50 to 95 weight percent of vinyl acetate, from 5 to 40 weight percent of at least one vinyl ester of a C5 to C18 unsaturated carboxylic acid, and optionally up to 40 weight percent of ethylene, all based on the total weight of monomers in the first monomer composition, to produce a first stage polymer. A second monomer composition comprising 40 to 89.95 weight percent of at least one ester of methacrylic acid or a vinyl aromatic monomer, 10 to 59.95 weight percent of at least one ester of acrylic acid, and from 0.05 to 10 weight percent of at least one comonomer with acid functionality, based on the total weight of monomers in the second monomer composition, is then polymerized in the presence of the first stage polymer to produce a second stage polymer.

Abstract: Cellulose acetate films having excellent optical properties are disclosed. The films are made from cellulose acetate and a plasticizer. A solvent cast precursor film is initially formed and then subjected to high temperatures and pressures for improving at least one optical property.

Abstract: Disclosed is a method for removing acetaldehyde and other permanganate reducing compounds (PRCs) from a process stream in the methanol carbonylation process for making acetic acid. The method includes the steps of forming an azeotrope to reduce the boiling point of the acetaldehyde and other PRCs to facilitate separation of the acetaldehyde and other PRCs from the process. In one embodiment the azeotrope comprises butane and acetaldehyde.

Abstract: A thermoplastic vulcanizate composition comprises: (i) a dispersed phase of rubber that is at least partially cured; (ii) a continuous thermoplastic phase including at least one thermoplastic polymer; (iii) a first polysiloxane comprising a migratory liquid siloxane polymer; and (iv) a second polysiloxane comprising a non-migratory siloxane polymer bonded to a thermoplastic material.

Abstract: In an embodiment, a thermoplastic vulcanizate (TPV) composition is provided. The TPV composition includes a thermoplastic polyolefin; and an ethylene based copolymer rubber, wherein the ethylene based copolymer rubber has: a Mw of from 500,000 g/mol to 3,000,000 g/mol, a Mw/Mn of 4.0 or lower, and a g?vis of 0.90 or greater. In another embodiment, a TPV composition includes a thermoplastic phase and an ethylene-propylene-diene terpolymer, wherein the thermoplastic vulcanizate composition has: a hardness of from 20 Shore A to 60 Shore D; and a stress relaxation slope of ?1 to ?5 (1/min) as measured by an Elastocon stress relaxation instrument.

Abstract: A process for forming stabilizing paraformaldehyde can include heating a formaldehyde solution comprising 30 wt % or more formaldehyde to a temperature ranging from about 70° C. to about 130° C.; aging the formaldehyde solution for a sufficient amount of time to polymerize the formaldehyde and form paraformaldehyde; solidifying the paraformaldehyde; and contacting the formaldehyde solution before and/or during heating, the formaldehyde solution during aging, the paraformaldehyde, and/or the solidified paraformaldehyde with an ammonia and/or ammonia hydroxide stabilizer.

Abstract: The present invention relates to preparation of heterogeneous mixtures of (carboxylated) vinyl ester/ethylene dispersions, such as vinyl acetate/ethylene (VAE) dispersions with polyamideamine-epichlorohydrin (PAE) wet strength resins having a reduced amount of halogenated organic compounds, such as less than 1500 ppm. The dispersion offers extremely low free and bound formaldehyde levels combined with wet tensile strength for use in non-woven textile and paper applications.