摘要:
Fibers and yarns of polyethylene terephthalate (PET) and PET copolymers with a sheath/filamentous core microstructure are formed from unoriented and non crystalline "as spun" source fibers and yarns by drawing to high draw ratios in one step. Fibers and yarns with the sheath/filamentous core microstructure are stiffer than commercial PET fibers. Fibers and yarns with the sheath/filamentous core microstructure may be annealed and relaxed to increase their dimensional stability without loss of the sheath/filamentous core microstructure.
摘要:
This invention provides a process for producing a carboxylate ester from a monoolefin and a carboxylic acid, in the presence of a solid catalyst comprising a composite of 5-sulfoisophthalic acid and a carrier substrate having a surface area between about 1-1000 m.sup.2 /gram.A carboxylate ester such as ethyl propionate is produced with a STY efficiency of at least 100 grams/liter hour.
摘要:
An improved catalyst is provided which is useful in hydroformylation reactions comprising a rhodium carbonyl complex and a polybenzimidazole fiber support wherein under hydroformylation conditions the rhodium carbonyl and complex forms a catalytically active polybenzimidazole complex with the benzimidazole units of the polybenzimidazole fiber surface acting as donor ligands for the rhodium carbonyl complex. This fiber supported catalyst may be readily separated from the products of the hydroformylation reaction by simple filtration.
摘要:
Disclosed herein is a method to produce a semi-crystalline fluoro-polymer film. A semi-crystalline fluoro-polymer material is used. The material is compressed to produce the film. During compression, the material is maintained at a temperature below the melting point of the material. The compression step can be cycled to allow cooling of the material between compression stages. Alternative methods are provided for compressing the material with a co-extrusion substrate, extruding the material and utilizing mandrel expansion for the material.
摘要:
A process for forming polymer powders by dissolving one or more polymers in a suitable solvent, followed by atomizing the solution into a droplet atmosphere of a non-solvent to precipitate polymer particles. The particles are separated from the non-solvent, washed and dried to produce a powder with a rounded particle morphology, high internal porosity and surface area, and high apparent density.Polymer powders with these properties can be pressed to dense shaped articles suitable for sintering in automated presses because the powders have good low and compressibility characteristics. The process if particularly useful when applied to soluble polymners that are not readily shaped by melt processing means.
摘要:
This invention provides a catalyst and process for achieving highly selective straight chain aldehyde formation from alpha-olefins under hydroformylation conditions. The improved hydroformylation results are obtained under mild conditions of temperature and pressure in the presence of a stabilized catalyst complex of rhodium metal, bidentate ligand and monodentate ligand represented by the formula: ##STR1## Illustrative of a preferred bidentate ligand is trans 1,2-bis(diphenylphosphinomethyl)cyclobutane. Illustrative of a preferred monodentate ligand is diphenylethylphosphine. It is an essential feature of the invention process that the monodentate ligand is provided in a molar excess with respect to the rhodium metal in the stabilized catalyst complex.
摘要:
This invention provides a process for achieving straight chain aldehyde formation from alpha-olefins with improved selectivity efficiency under hydroformylation conditions. The improved hydroformylation results are obtained under mild conditions of temperature and pressure in the presence of a stabilized catalyst complex of rhodium metal, bidentate ligand and monodentate ligand represented by the formula: ##STR1## Illustrative of a preferred bidentate ligand L is 1,1'-bis-(diphenylphosphino)ferrocene. Illustrative of a preferred monodentate ligand L' is diphenylethylphosphine. It is an essential feature of the invention process that the monodentate ligand is provided in a molar excess with respect to the rhodium metal in the stabilized catalyst complex.
摘要:
Injection moldable, highly filled polymer composites are provided which exhibit high dimensional stability at temperatures above the glass transition temperature of the matrix polymer. The heat distortion temperature of the composites approaches that of the crystal melting temperature of the matrix polymer. The composite includes a polyaryletherketone matrix and at least two types of fillers each providing unique properties. The first filler is a reinforcing fiber filler which provides high strength and stiffness. The second filler is an non-thermoplastic immobilizing filler to immobilize the amorphous portion of the partially crystalline polyaryletherketone polymer and provide resistance to high temperature distortion. Notwithstanding its improved mechanical and heat resistant properties, the composite remains injection moldable and thus capable of low cost manufacturing.
摘要:
Cubelets are made from a piezoelectrically active ceramic material having holes therein which may be cross-cored. The holes are selectively filled with a liquid curable resin, such as an epoxy. The cubelets may also be formed from bonded or sintered "half-shapes" containing half cores, wherein a face bisects one hole or an array of holes or cross-cored holes to form one or an array of semicircular grooves or crossed semicircular grooves. The cubelets, whether filled with resin or having unfilled internal volume, are arranged in a precision array within the snug-fitting cavities of a lattice, whereby the holes are sealed off, to form a cubelet/lattice assembly which is then electroded and poled in an electric field and encapsulated in polymer to form a part of a hydrophone assembly, for example.
摘要:
This invention provides a process for producing a carboxylate ester from a monoolefin and a carboxylic acid, in the presence of a solid catalyst comprising a composite of 5-sulfoisophthalic acid and a carrier substrate having a surface area between about 1-1000 m.sup.2 /gram.A carboxylate ester such as ethyl propionate is produced with a STY efficiency of at least 100 grams/liter hour.