Abstract:
The present invention provides an improved process and apparatus for alkanolysis of polytetramethylene ether diacetate to polytetraalkylene ether glycol in the presence of a C1 to C4 alkanol and an alkali or alkaline earth metal catalyst wherein the catalyst component of the product mixture comprising polytetraalkylene ether glycol, alkanol and catalyst, essentially free of the alkanol acetate by-product, e.g., methyl acetate is removed by contacting the mixture in the absence of added water with certain ion exchange resin at specified contact conditions. The invention further provides a highly efficient method for removing the catalyst component of a mixture comprising polytetraalkylene ether glycol, alkanol and alkali or alkaline earth metal catalyst by contacting the mixture in the absence of added water with certain ion exchange resin at specified contact conditions,
Abstract:
A method for preventing pressure build-up across a catalyst separation in a polyether polyol reactor comprising the steps of feeding reactants that comprise a monomer or co-monomers to be polymerized to form the polyether polyol into a continuous feed reactor, flowing the product stream through a catalyst separation system within the reactor, wherein the catalyst separation system is comprised of a plurality of filters, wherein each filter comprises an outer surface and an inner surface defined by a plurality of spaced-apart elements, and wherein the distance between the spaced-apart elements is smaller than the minor dimension of the suspended catalyst and recovering the filtered polyether polyol product and catalyst fines from the reactor outlet.
Abstract:
Disclosed are processes and systems for manufacturing polyethylene terephthalate (PET) and pre-polymer. The processes and systems use a variable pressure drop up-flow-pre-polymerizer configuration. The pressure profile in the UFPP can be selected to beneficially change the relative reaction rates of the polymerization and esterification reactions. This design maximizes the esterification carried out in the UFPP, while still producing a pre-polymer with the optimum carboxyl end groups concentration {e.g., about 30 μ equiv./g to 60 μ equiv./g) to maximize finisher productivity. This can result in a reduction of the size and cost of the esterifier required for a given plant throughput.
Abstract:
Disclosed are processes and systems for the improved production of aromatic carboxylic acids, such as purified terephthalic acid. The processes result in the use of a smaller distillation device to more efficiently recover the carboxylic acid solvent throughout various stages of the PTA process when compared to known processes. The smaller distillation device is achieved by using downstream water treatment devices and organic compound extraction devices to further separate organic compounds from the aqueous byproduct streams.
Abstract:
Polyamide terpolymer compositions, which contain biobased monomers and are suitable for making shaped articles, are disclosed. Comprised of three monomeric species polymerized randomly, including hexamethylene diamine, adipic acid and a bio-based monomer, the compositions are easier to process and have better dye uniformity than polyamides formed from melt-blended biobased components, and are comparable in dyeability, color fastnessand appearance retention performance to non-biobased polyamide copolymers.
Abstract:
This invention relates to systems and methods to recover heat and scrub the off-gas from oxidation reactors in a process to produce aromatic carboxylic acids, such as terephthalic acid.
Abstract:
Methods of making a composition are disclosed, which comprises: i) forming a dispersion of particles comprising: a) silica, b) a non- volatile cation, and c) water, wherein the non-volatile cation is not ammonium; ii) adding at least one organosilyl coupling agent of formula R 1 -(R 2 -O) 3 -Si where R 1 is selected from the group consisting of a substituted alkyl and unsubstituted alkyl, and R 2 is selected from the group consisting of methyl, ethyl, propyl and butyl, wherein the substituted alkyl of R 1 is not aminoalkyl; iii) reacting the organosilyl coupling agent with the dispersion of particles to form a mixture comprising a silsesquioxane and an alcohol; and iv) removing the alcohol from the mixture by vacuum distillation, wherein final concentration of the alcohol is about 1% by weight or less of the total mixture. Further disclosed are compositions comprising an aqueous dispersion comprising silsesquioxane, a non- volatile cation and an alcohol, and methods of using the composition.
Abstract:
Included are multiple component elastic fibers prepared by a solution-spinning process such as dry spinning or wet spinner of spandex fibers including polyurethaneurea and polyurethane compositions. These fibers have a cross-section including at least two separate regions with definable boundaries wherein at least one region defined by the boundaries of the cross-section includes a polyurethaneurea or polyurethane composition. One region of the fiber includes a fusibility improvement additive to enhance adhesion to itself or to a substrate.
Abstract:
Briefly described, embodiments of this disclosure include close-couple twisting and heat-setting apparatus, methods of twisting yarn and heat-setting twisted yarn, and the like.