摘要:
Rigid urea-modified polyisocyanurate foams with improved dimensional stability and flame retardancy have densities of 0.5-20 p.c.f., a limiting oxygen index greater than 22 and dimensional changes at 100% R.H. and 70.degree. C. of less than 2% in any linear dimension and a method of making same. The method comprises reacting an organic polyisocyanate, a blowing agent and an N,N'-dialkyl aromatic diamine in the presence of a trimerization catalyst and, if water is used as the blowing agent, a blowing catalyst, wherein the N,N'-dialkyl aromatic diamine and an amine produced by water, if used, constitute the sole sources of active hydrogen.
摘要:
The polyurethanes and polyureas resulting from ambient-temperature-curing isocyanate-terminated urethane prepolymers with N-alkyl-substituted aromatic polyamines and, optionally, with an added polyol, but primary amine-free, in the presence of a combination catalyst comprising an aliphatic carboxylic acid, e.g., adipic, stearic, oleic acids, and an organometallic catalyst containing, e.g., tin, mercury, bismuth, etc. are broadly useful as coating on the surface of objects made of metal, wood, glass, plastic or masonry materials such as concrete, bricks, etc. or as castings cured in situ. One-shot and quasi-prepolymer systems are also disclosed. The diamine N,N'-di-(sec-butyl)-4,4'-methylenedianiline is a particularly useful diamine.
摘要:
N,N'-disubstituted diamines are effective curing agents in combination with other polyamines and polyols in reaction injection molding for a diverse class of polyisocyanates. The diamines provide a broad spectrum of cure times, as well as giving elastomers an interesting and useful diversity of properties. Such diamines may be used as a constituent in a blend of polyamines as the isocyanate-reactive component, in which case the elastomer may be viewed as predominantly a polyurea, or as a constituent in a blend with polyols, in which case the elastomer may be viewed as an elastomer with both urethane and urea segments.
摘要:
The polyurethanes resulting from curing isocyanate-terminated urethane prepolymers with a N,N'-dialkylmethylenedianiline are broadly useful as coatings on the surface of objects made of metal, wood, glass, or plastic. Such coatings may be made based on either a 1-pack systemor 2-pack system. The diamine N,N'-di(2-butyl)4,4'-methylenedianiline is a particularly useful diamine.
摘要:
Largely alkylated polyamines which may be viewed as low molecular weight polymers of x-amino-y-methylenephenyl are effective curing agents for a diverse class of urethane prepolymers. The resulting polyurethanes are thermosetting polymers with excellent compression set and tensile strength. Because the properties of the resulting polyurethane vary only slightly near the optimum stoichiometry of curing agent-prepolymer, the use of the curing agents of this invention presents the advantage of being very tolerant of operator mixing error.
摘要:
The polymers resulting from reaction of a 1,1,2,2-tetrahaloethane with a diamine of the type H.sub.2 NANH.sub.2, where A is a divalent aromatic moiety, may be doped with a variety of materials to afford electrically conducting polymeric compositions. Poly(ethyleneiminobenzene) is an especially useful material which may be prepared in good yield from the reactants in a dipolar aprotic solvent in the presence of a base.
摘要:
Although poly(nitrilo-1,4-phenylene nitrilomethylidine-1,4-phenylene methylidine) is an insulator, it can be doped with both electron acceptors and electron donors to afford p- and n-type semiconductors. The iodine doped material is more stable in air than many prior art conducting polymers.
摘要:
Flexible foam resistant to both photochemical and oxidative degradation result from the use of bis(N-alkylaminocyclohexyl)methanes as curing agents for polyisocyanates or polyisocyanate prepolymers. The chain extenders may be used alone or in combination with other polyamines and with polyols. Where the polyisocyanate or polyisocyanate prepolymer is also aliphatic there is outstanding resistance to yellowing.
摘要:
Rigid urea-modified polyisocyanurate foams with improved dimensional stability and flame retardancy have densities of 1-12 p.c.f., a limiting oxygen index greater than 22 and dimensional changes at 100% R.H. and 70.degree. C. of less than 2% in any linear dimension and a method of making same. The method comprises reacting an organic polyisocyanate, a blowing agent and an N,N'-dialkyl aromatic diamine in the presence of a trimerization catalyst and, if water is used as the blowing agent, a blowing catalyst, wherein the N,N'-dialkyl aromatic diamine and an amine produced by water, if used, constitute the sole sources of active hydrogen.
摘要:
N,N'-dialkyl- and diarylphenylenediamines are effective curing agents in combination with other polyamines and polyols in reaction injection molding for a diverse class of polyisocyanates. The diamines provide a broad spectrum of cure times, as well as giving elastomers an interesting and useful diversity of properties. Such polyamines may be used as a constituent in a blend of polyamines as the isocyanate-reactive component, in which case the elastomer may be viewed as predominantly a polyurea, or as a constituent in a blend with polyols, in which case the elastomer may be viewed as an elastomer with both urethane and urea segments.