Abstract: Hybrid yarn is produced from thermoplastic and reinforcing fibers by spreading the fibers separately to form a band and combining and homogeneously intermixing the two bands on rolls or rods. The spreading is carried out in such a way that the reinforcing fiber band will be from 20 to 100% wider than the thermoplastic fiber band. The hybrid yarn can be sized and processed into fabrics which can be molded to produce fiber composites.

Abstract: Addition of minor quantities of mono- or dicarboxylic acids to polyurethane foam formulations which employ polyisocyanate polyaddition polymer polyol dispersions prevents shrinkage and tightness in polyurethane foams prepared therefrom. If acid addition is made directly after dispersion preparation, reduction of polyol viscosity and more rapid stabilization against viscosity change is observed.

Abstract: A process for the preparation of cellular polyurethane elastomers involves reactinga) an organic and/or modified organic polyisocyanate withb) a polyether polycarbonate diol which contains bonded polyoxytetramethylene glycol radicals having a mean molecular weight Mn (number average) of from 150 to 500, and, if desired,c) a low-molecular-weight chain extender and/or crosslinking agent,in the presence ofd) a blowing agent,e) a catalyst andf) if desired additives and/or assistants.

Abstract: Radomes having increased transparency and reduced reflectivity and refractivity to radar waves may be prepared or repaired utilizing heat-curable resin-containing structural materials in which the heat-curable resin contains greater than about 70 weight percent of cyanate functional monomers. The structural materials take the form of matrix resin impregnated prepegs and composites, film adhesives, paste adhesives, syntactic foams, and expandable foams, and may be used to prepare numerous useful structural features including honeycomb materials and leading edge radomes containing syntactic foams.

Abstract: The present invention relates to a process for the production of elastic, compact or cellular moldings based on elastomers containing N-benzylurea groups in bound form, by reactinga) one or more organic and/or modified organic polyisocyanates withb) N-benzylpolyoxyalkylene-polyamines or mixtures of N-benzylpolyoxyalkylene-polyamines and polyoxyalkylene-polyamines containing from 2 to 4 primary amino groups andc) one or more alkyl-substituted aromatic polyamines having a molecular weight of up to 500,in the presence or absence ofd) catalystsand, if desired,e) blowing agents,f) auxiliaries and/org) additives,and to the N-benzylpolyoxyalkylene-polyamines and mixtures of N-benzylpolyoxyalkylene-polyamines and polyoxyalkylene-polyamines containing from 2 to 4 primary amino groups which can be used for this purpose, and to the elastomers prepared.

Abstract: Heat-curable bismaleimide resins contain a bismaleimide, an aromatic dialkenyl compound as comonomer and also from 1 to 40% by weight of a monoalkenyl compound, preferably 2-hydroxy-3-allylbiphenyl, as reactive diluent.

Abstract: A sizing agent for carbon fibers and glass fibers is based on an aqueous dispersion containing an epoxy resin and from 5 to 40% by weight, based on the epoxy resin, of a nonionic emulsifier containing teritary amino groups and/or ether linkages and at least one functional radical capable of reaction with the epoxy resin, preferably a glycidyl radical, and also at least one emulsifying radical which preferably carries a polyethylene glycol group in the terminal position.

Abstract: Fiber-reinforced thermoplastic honeycomb is prepared in a continuous manner one half cell at a time by laying down a corrugated web of thermoplastic, with and without fiber-reinforcement atop a honeycomb, selectively fusing the node-antinode demes and repeating the process until a honeycomb of the desired depth is prepared.

Abstract: Radomes having increased transparency and reduced reflectivity and refractivity to radar waves may be prepared or repaired utilizing heat-curable resin-containing structural materials in which the heat-curable resin contains greater than about 70 weight percent of cyanate functional monomers. The structural materials take the form of matrix resin impregnated prepegs and composites, film adhesives, paste adhesives, syntactic foams, and expandable foams, and may be used to prepare numerous useful structural features including honeycomb materials and leading edge radomes containing syntactic foams. The heat-curable resins further facilitate the preparation of low observable structures.

Abstract: Low and high density structural RIM compositions are disclosed which have low viscosities. These compositions contain a resin "B-side" component which comprises a hydroxyl-functional tertiary amine polyol.

Abstract: Novel esters containing bonded fluorocarbon and oxypropylenealkylether groups and of the formula ##STR1## where Rf is straight-chain or branched, partially fluorinated or perfluorinated alkyl of 2 to 10 carbon atoms, partially fluorinated or perfluorinated cycloalkyl of 4 to 8 carbon atoms,perfluorophenyl orperfluoroalkylphenyl where the perfluoroalkyl radical is of 1 to 6 carbon atoms,R is straight-chain or branched alkyl of 1 to 4 carbon atoms andn is an integer from 2 to 70,blowing agent-containing emulsions which have a long shelf life and contain at least one partially fluorinated or perfluorinated (cyclo)aliphatic hydrocarbon of 3 to 8 carbon atoms and/or sulfur hexafluoride, at least one unmodified or modified organic polyisocyanate or a relatively high molecular weight reactive hydrogen compound and at least one of the abovementioned carboxylic or carbamic esters, and the use of these emulsions for the preparation of cellular plastics by the polyisocyanate polyaddition method.

Abstract: A recyclable bumper system based on polypropylene comprises a bumper support A of glass fiber reinforced polypropylene, an energy-absorbing foam core B of foamed polypropylene and a tough shell C of EP-rubber modified polypropylene which may be coated, and can be recycled by mechanical comminution, extrusion and granulation, resulting in granules from which injection moldings having good mechanical properties can be produced.

Abstract: The present invention relates to a process for the production of elastic, compact or cellular moldings based on elastomers containing N-benzylurea groups in bound form, by reactinga) one or more organic and/or modified organic polyisocyanates withb) N-benzylpolyoxyalkylene-polyamines or mixtures of N-benzylpolyoxyalkylene-polyamines and polyoxyalkylene-polyamines containing from 2 to 4 primary amino groups andc) one or more alkyl-substituted aromatic polyamines having a molecular weight of up to 500,in the presence or absence ofd) catalystsand, if desired,e) blowing agents,f) auxiliaries and/org) additives,and to the N-benzylpolyoxyalkylene-polyamines and mixtures of N-benzylpolyoxyalkylene-polyamines and polyoxyalkylene-polyamines containing from 2 to 4 primary amino groups which can be used for this purpose, and to the elastomers prepared.

Abstract: Toughened bismaleimide resin systems capable of preparing carbon fiber reinforced composites having compression after impact strengths of greater than 40 Ksi are prepared from bismaleimide matrix resin systems containing a member of a limited set of soluble thermoplastic polyimides in particulate form.

Abstract: Compositions are disclosed which are suitable for the preparation of thermoplastic syntactic foam intermediate and final products. These compositions comprise a slurry or putty containing thermoplastic particles, microballoons, and a non-solvent, optionally in the presence of suitable thickeners, binders, and surfactants. In a preferred embodiment, the composition contains particles of an engineering thermoplastic having a mean particle size less then about 100 .mu.m, microballoons, water as the non-solvent, and a thickener/binder which is a lightly crosslinked polyacrylic acid.

Abstract: Polyether polyols prepared by oxyalkylating a 1,2-diaminocycloalkane have reduced levels of unsaturation and may be used to prepare melamine containing flame retardant polyurethane foams capable of passing California 117 and 133, and other flame tests.

Abstract: Macromers for use in preparing stable, low viscosity graft polymer polyols of high solids content are disclosed. These macromers are easily made in high yield with short cycle times, and may be used to prepare graft dispersions containing amine based polyols.

Abstract: Solid, fusible bismaleimide resins formed from a mixture of a bismaleimide and an aminophenol still contain from 70 to 90 mol % of unconverted bismaleimide and from 30 to 60 mol % of unconverted aminophenol.

Abstract: In a multilayer panel comprising a core layer A with a honeycomb structure or an open-celled foam structure and at least one cover layer C made of a fiber-reinforced thermoplastic polymer, layers A and C are bonded to one another by an adhesive B which is a thermoplastic polymer.

Abstract: The invention relates to a process for the production of elastic, compact or cellular moldings based on elastomers containing N-substituted urea and amide groups in bound form, by reactinga) one or more organic and/or modified organic polyisocyanate withb) a polyazomethine-containing polyoxyalkylene-polyamine mixture (b) which contains:bi) one or more polyoxyalkylene-polyaldimine and/or polyketimine,bii) one or more polyoxyalkylene-polyamine containing terminal secondary amino groups, and, if desired,biii) one or more polyoxyalkylene-polyamine containing terminal primary amino groups andc) one or more alkyl-substituted aromatic polyamine having a molcular weight of up to 500, in the presence or absence ofd) catalyst, and, if appropriate,e) blowing agents,f) auxiliaries and/org) additives,to polyazomethine containing polyoxyalkylene - polyamine mixtures which can be used for this purpose and to the prepared elastomers.