Abstract:
The invention relates to a crosslinker composition comprising a reaction product of a cyclic urea U and a multifunctional aliphatic aldehyde A, and at least one crosslinker selected from the group consisting of reaction products of an aminotriazine and at least one aldehyde selected from the group consisting of aliphatic monoaldehydes and multifunctional aliphatic aldehydes having the structure Y(CHO) n , where Y is an n-functional aliphatic residue, and n is greater than 1; reaction products of urea and/or cyclic ureas and formaldehyde; alkoxycarbonyl- aminotriazines; multifunctional isocyanates which may be partially or completely blocked; reaction products of phenols and aliphatic monoaldehydes; multifunctional epoxides; multifunctional aziridines; and multifunctional carbodiimides, wherein any of the crosslinkers which have hydroxyl groups may be etherified with one or more linear, branched, or cyclic aliphatic alcohols.
Abstract:
Thermosettable prepolymers or resins are prepared by reacting a pyrazine containing at least two substituent groups which have a hydrogen atom attached to a carbon atom which is attached to the ring, with a material containing at least two aromatic aldehyde groups. These prepolymers or resins are curable to thermoset products having good mechanical and thermal properties. Thermoset polymers having good mechanical and thermal properties are also prepared by homopolymerization in the presence of N,N'-bis-imides or copolymerization of these prepolymers with N,N'-bis-imides. The prepolymers are suitable for preparing composites.
Abstract:
Heat resistant thermosetting prepolymers are prepared by reacting one or more methylated pyridines or pyrazines with one or more aromatic dialdehydes, and isopropenyl phenols. The prepolymers can be further reacted with bismaleimides to make prepolymers with lower cure temperatures and faster cure rates. The total number of methyl groups on the pyridine or pyrazine can vary from 2 to 4. The prepolymers are cured to produce heat resistant polymers and laminates with conventional fibers such as carbon fibers.
Abstract:
The present invention relates to a method for preparing a metallized open-cell foam or fibrous substrate, wherein the method comprises: (A) providing an open-cell foam or fibrous substrate, wherein the open-cell foam or fibrous substrate contains a polymer comprising heteroatom-containing moieties within the bulk of the open-cell foam or fibrous substrate or as a coating on the open-cell foam or fibrous substrate, wherein the polymer comprising heteroatom-containing moieties is selected from polyvinylpyridine, polyvinylpyrrolidone, polyvinyl alcohol, polyallylamine, polyethylene oxide, polyethylene imine, polyethylene sulfide and copolymers or blends thereof; (B) contacting the open-cell foam or fibrous substrate with nanoparticles of a first metal to provide a nanoparticle coated open-cell foam or fibrous substrate; and (C) contacting the nanoparticle coated open-cell foam or fibrous substrate with a solution comprising a salt of a second metal and a reducing agent to provide the metallized open-cell foam or fibrous substrate having a layer of the second metal on the nanoparticle coated open-cell foam or fibrous substrate.
Abstract:
This invention relates to aminoplast crosslinker resins compositions based on at least partially alkylated reaction products A of melamine, formaldehyde and an alkanol with the following parameters: the ratio of the amount of substance n(CH2O) of combined formaldehyde to the amount of substance n(Mel) of melamine is in the range of from 5.6 mol/mol to 6.2 mol/mol, the ratio of the amount of substance n(RO) of alkyl ether groups in the crosslinker resin to the amount of substance n(Mel) of melamine is in the range of from 5.0 mol/mol to 5.6 mol/mol, the mass fraction of monomer in the resin, calculated as the ratio of the mass of monomer m(1) to the mass m(A) of the reaction products A is between 35 % and 55 %, to a process for their preparation, and to a method of use thereof as crosslinker in combination with hydroxy- functional polymers for coating of heat-sensitive substrates.
Abstract:
This invention is directed to cured fibrous composites prepared from the resinous reaction products of hydroxy aromatic mono-aldehydes and methylated pyridines or methylated pyrazines. This invention is also directed to thermosettable prepolymers prepared from hydroxy aromatic mono-aldehydes and methylated pyrazines. The total number of methyl groups in the pyridine or pyrazine ranges from 2 to 4. The composites are prepared from conventional fibers such as graphite fibers, glass fibers, aramid fibers, or asbestos fibers.
Abstract:
This invention relates to aminoplast crosslinker resins compositions based on at least partially alkylated reaction products A of melamine, formaldehyde and an alkanol with the following parameters: the ratio of the amount of substance n (CH 2 O) of combined formaldehyde to the amount of substance n (Mel) of melamine is in the range of from 5.6 mol/mol to 6.2 mol/mol, the ratio of the amount of substance n (RO) of alkyl ether groups in the crosslinker resin to the amount of substance n (Mel) of melamine is in the range of from 5.0 mol/mol to 5.6 mol/mol, the mass fraction of monomer in the resin, calculated as the ratio of the mass of monomer m (1) to the mass m (A) of the reaction products A is between 35 % and 55 %, to a process for their preparation, and to a method of use thereof as crosslinker in combination with hydroxy- functional polymers for coating of heat-sensitive substrates.