Abstract: A process for preparing a polyarylene sulfide involves dehydrating a mixture of a hydrous sulfur source and an organic polar solvent under a reduced pressure in a rectification tower and contacting a dihalogen aromatic compound with a dehydrated sulfur source in the organic polar solvent.This process provides the polyarylene sulfide with a white color and a higher molecular weight.
Abstract: Crystallizable polyphthalamides with a useful combination of thermal and mechanical properties comprising recurring moieties of terephthalic acid, adipic acid, an aliphatic diamine of 4 to 20 carbon atoms and meta-xylylene diamine.
Abstract: A thermosetting resin composition, and a resin sheet, a prepreg and a laminated sheet using the composition are disclosed, which composition comprises (A) an amine-terminated oligomer represented by formula (I): ##STR1## wherein Ar.sub.1 represents a divalent aromatic group, AR.sub.2 represents a tetravalent aliphatic or aromatic group, and a represents an integer of at least 1; and (B) a polymaleimide represented by formula (II): ##STR2## wherein Ar.sub.3 represents an aliphatic group having two or more carbon atoms or an aromatic group, and b represents an integer of at least 2, provided that a part of the whole of hydrogen atoms of at least one group of Ar.sub.1, Ar.sub.2 and Ar.sub.3 in formulae (I) and (II) is substituted by fluorine atoms.
Abstract: Peroxy-terminated polycarbonates are prepared by the reaction of an aromatic dihydroxy compound, preferably a bisphenol, with phosgene in one or two steps, in the presence of a peroxy ester such as the mono-t-butyl perester of maleic acid. The peroxy-terminated polycarbonates may be employed to initiate vinyl polymerization of ethylenically unsaturated monomers or to react with polymers containing ethylenically unsaturated groups, to form copolymers which are useful as compatibilizers for blends of polycarbonates with said polymers.
Abstract: A process of preparing homopolymers and copolymers of dodecane terephthalamide having a high melting temperature and dimensional stability, comprising the steps of forming an aqueous suspension of a prepolymer comprising substantially equimolar diacid/diamine admixture of 1,12-dodecanediamine, terephthalic acid, and optionally at least one additonal comonomer in a reactor at a reaction temperature below the melting temperature of the resulting polyamide polymer; drying the prepolymer; and polycondensating the dried prepolymer in an extruder, particularly a vented single screw extruder, to form the polyamide polymer.
Type:
Grant
Filed:
January 8, 1992
Date of Patent:
March 2, 1993
Assignee:
Allied Signal
Inventors:
Murali K. Akkapeddi, Michael F. Cummings, Gerald J. Dege
Abstract: Branched polycarbonates are prepared by melt equilibration of aromatic cyclic polycarbonate oligomes with a polyhydric phenol having more than two hydroxy groups per molecule, preferably 1,1,1-tris-(4-hydroxyphenyl)ethane, in the presence of a carbonate equilibration catalyst, preferably tetrabutylammonium tetraphenylborate. In an additional embodiment of the invention, a linear aromatic polycarbonate is added to the reaction mixture. Branched polycarbonates prepared according to this invention have high melt strength and high shear sensitivity characteristics and are useful in extrusion and injection molding processing applications and particularly useful in blow molding applications for preparing relatively large articles and panels.
Abstract: The compound N-(3-ethynylphenyl)maleimide (NEPMI) was used to prepare thermally stable, glassy polyimides which did not exhibit glass transition temperatures below 500.degree. C. NEPMI was blended with the maleimide of methylene dianiline (BMI) and heated to form the polyimide. NEPMI was also mixed with Thermid 600.RTM., a commercially available bisethynyl oligomeric material, and heated to form a thermally stable, glassy polyimide. Lastly, NEPMI was blended with both BMI and Thermid 600.RTM. to form thermally stable, glassy polyimides.
Type:
Grant
Filed:
December 3, 1991
Date of Patent:
February 23, 1993
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: A process for the preparation of a polycarbonate comprising reacting a diaryl carbonate with a bisphenol to produce a polycarbonate and a phenol, regenerating the diaryl carbonate by reacting the phenol byproduct with a carbonyl halide, and optionally recycling the hydrogen halide using a metal Redox captive halogen swing reactor system.
Abstract: Thermally stable, glassy polymeric materials were prepared from maleimideacetylene terminated monomeric materials by several methods. The monomers were heated to self-polymerize. The A-B structure of the monomer allowed it to polymerize with either bismaleimide monomers/oligomers or bis-acetylene monomers/oligomers. Copolymerization can also take place by mixing bismaleimide and bisacetylene monomers/oligomers with the maleimide-acetylene terminated monomers to yield homogenous glassy polymers.
Type:
Grant
Filed:
December 3, 1991
Date of Patent:
February 23, 1993
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: A polycarbonate pellet having a size between 200 and 1,500 microns, not inclusive, is produced by extruding molten polycarbonate through a die and cutting such extrudate with a die face cutter.
Abstract: An improved process for preparing linear interpolymers of olefin(s) (e.g. ethylene) and carbon monoxide (Polyketones) is provided. The process comprises polymerizing the olefin(s) with carbon monoxide in the presence of a palladium catalyst derived from a palladium source, a bidentate amine, phosphine, arsine or stibine of formula (R.sup.1).sub.2 M--R.sup.2 --M(R.sup.1).sub.2 where the M atoms are selected from N, P, As or Sb, the R.sup.1 groups are e.g. C.sub.1 to C.sub.4 alkyl or phenyl and R.sup.2 is e.g. (CH.sub.2).sub.a where a=2 to 10, and a anion prepared by reacting in a 2:1 molar ratio and substituted salicylic acid and boric acid. The salicylic acid is preferably 4- or 5- substituted with methyl, Cl or Br. Using this particular palladium catalyst leads to high polymer yields than e.g. when unsubstituted salicylic acid is employed.
Abstract: Disclosed is a novel polycarbonate which has(1) a repeating unit (I) represented by the general formula: ##STR1## and a repeating unit (II) represented by the formula: ##STR2## (All the symbols are as defined in the claims); (2) a trihalogenophenoxy group as the end group thereof; and (3) a viscosity average molecular weight of 10,000 to 50,000 and 1 to 10 mol % of the repeating unit (I) in the main chain.The polycarbonate is excellent in all of flame retardance, impact resistance, and a thermostability at molding. Accordingly, the polycarbonate of the present invention is extensively and effectively used as various industrial materials such as home electric appliances, office automation devices, construction materials and the like.
Abstract: Copolyamides are prepared by the non-catalytic polymerization of an omega-aminonitrile with a mixture of a diamine and a dicarboxylic acid. Not more than 40% by weight of the product is derived from the omega-aminonitrile.
Abstract: A copolyadipamide consisting essentially of between about 60 and about 99.5 mole percent hexamethyleneadipamide units and between about 0.5 and 40 mole percent pentamethyleneadipamide units, the copolyamide having an RV greater than about 25, and a melting point of greater than about 220.degree. C.
Abstract: Poly(1,2,4-triazoles)(PT) have been prepared by involving the aromatic nucleophilic displacement reaction of di(hydroxyphenyl)-1,2,4-triazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions are carried out in polar aprotic solvents such as sulfolane or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl)-1,2,4-triazole monomers are first synthesized by reacting bis(4-hydroxyphenyl) hydrazide with aniline hydrochloride at 250.degree. C. in the melt and also by reacting 1,3 or 1,4-bis-(4-hydroxyphenyl)phenylenedihydrazide with 2 moles of aniline hydrochloride in the melt. Purification of the di(hydroxyphenyl)-1,2,4-triazole monomers is accomplished by recrystallization.
Type:
Grant
Filed:
January 24, 1991
Date of Patent:
January 26, 1993
Assignee:
The United States of America as represented by the United States National Aeronautics and Space Administration
Inventors:
John W. Connell, Paul M. Hergenrother, Peter Wolf
Abstract: The invention relates to a method of preparing aromatic polycarbonate having a high molecular weight by boundary face condensation of carbonate oligomer in the presence of an aromatic monohydroxy compound as a chain stopper, base, water and organic solvent at a temperature of at most 70.degree. C., in which the components, among which the chain stopper, are mixed in static mixers to form a fine dispersion, reacting these in a residence zone with plug flow and repeating these steps at least once.
Type:
Grant
Filed:
July 29, 1991
Date of Patent:
January 26, 1993
Assignee:
General Electric Company
Inventors:
Hendricus H. Maria van Hout, Martin H. Oyevaar, Bert J. Held
Abstract: Disclosed is a process for producing powder aggregate particle of high molecular weight polycarbonate resin which comprises adding a poor solvent to a solution containing 3 to 8% by weight of high molecular weight polycarbonate resin having a viscosity average molecular weight of at least 70,000 in a solvent in a ratio of the poor solvent to the solution of the polycarbonate resin of 0.2 to 0.6 by volume, continuously pouring the resulting mixture into water heated to a higher temperature than a boiling point of a solvent of the solution of the polycarbonate resin, thereby suspending the mixture in the warm water, distilling out the solvent and the poor solvent from the mixture, thereby obtaining a slurry of the polycarbonate resin and water in the following ratio by volume:Solvent/polycarbonate resin.ltoreq.0.55Solvent/poor solvent.ltoreq.0.7,and recycling at least a portion of the slurry to a wet-process pulverizer, while further distilling out the solvent and the poor solvent from the slurry.
Abstract: The invention relates to alkyl- or aryl-terminated polyamide compositions and polyamide rheological additives that function as a sag/slump control agent and provide superior shear-thinning and viscosity recovery properties in systems that react with or are sensitive to water and other active hydrogen containing materials and systems that do not react with or are not sensitive to water or other active hydrogen containing materials, and are useful in sealants, caulks, adhesives and coatings.
Abstract: A polyketone having a molecular weight greater than 1,000 and containing 0.01 to 50 mole percent carbonyl groups is contacted directly with an organic peroxyacid to produce a polyester. The polyketone is in a single homogenous phase during the oxidation process and may be in either solid or liquid form.In a preferred embodiment, a molten polyketone is contacted with an organic peroxyacid in a reactive extrusion process to produce polyester pellets.