摘要:
Described herein are curable molding compositions comprising a mixture of:(a) a vinyl ester produced by the addition of an unsaturated monocarboxylic acid to a polyepoxide and having a molecular weight greater than 300;(b) acrylic or methacrylic acid or a functionalized derivative thereof having a molecular weight of less than 300;(c) an ethylenically unsaturated monomer which is soluble in and copolymerizable with (a) and (b) and which is different from (b).The compositions can also contain one or more fibers with a melting point or a glass transition temperature above about 130.degree. C.
摘要:
The invention relates to silicone surfactants having the general formula:MD.sub.x D'.sub.y Mwherein M is a (CH.sub.3).sub.3 SiO.sub.0.5 -- group; D is a --(CH.sub.3).sub.2 SiO-- group; D is a --(CH.sub.3)(R.sup.2)SiO-- group, in which R.sup.2 is a non-linear hydrocarbyl group; x is 0 or an integer from 1 to 20 and y is an integer from 1 to 20. The silicone surfactants of the present invention are effective polyurethane foam stabilisers and are effective in amounts smaller than previously used commercially thereby leading to savings in costs.
摘要:
A process for producing acrylic ester by the catalytic esterification of a crude liquid stream of enriched acrylic acid recovered by the partial condensation of the reaction gas effluent from the catalytic oxidation of propylene and/or acrolein. The partial condensation allows a significant proportion of volatile aldehydes and water to pass through the first recovery stage to a second stage for conventional recovery, along with uncondensed acrylic acid vapors and the remainder of the uncondensed reaction gases.
摘要:
Linear silicone-urethane copolymers which contain tertiary amine or quaternary ammonium groups on the polymer backbone of the general formula:{R'NR"SiMe.sub.2 (OSiMe.sub.2).sub.b OSiMe.sub.2 R"NR'CONHR"NHCO.sub.2 (Y)O.sub.2 CNHR"NHCO}wherein Me represents a methyl group; R' represents a hydrogen atom or a lower alkyl group having one to three carbon atoms; R" represents a divalent hydrocarbon group having at least three carbon atoms such as (CH.sub.2).sub.3-12 ; and Y represents (C.sub.z H.sub.2Z+1 N) where Z.gtoreq.5 and .ltoreq.22 and may be quaternized by use of a quaternizing agent R'X wherein X is selected from the group consisting of a halide atom, an acetate or higher carboxylate group, and an alkylsulfate group where the alkyl moiety has 1 to 12 carbon atoms and where R', R" and b may vary within each copolymer are described. These copolymers may be cast from organic solvents or from aqueous dispersions, providing films which possess high degrees of clarity and unexpectedly high strength and elasticity.
摘要:
A process is provided for the epoxidation of an alkene in the presence of an oxygen-containing gas which comprises contacting the alkene and the oxygen-containing gas under epoxidation conditions in the presence of at least one efficiency-enhancing gaseous member of a redox-half reaction pair and a solid catalyst, the catalyst comprising a catalytically-effective amount of silver on a solid support and an efficiency-enhancing amount of at least one efficiency-enhancing salt of a member of a redox-half reaction pair, the support having less than about 50 ppm, by weight, of leachable sodium.
摘要:
A process for producing sticky polymers at polymerization reaction temperatures in excess of the softening temperature of the sticky polymers in a fluidized bed reactor catalyzed by a transition metal catalyst, which comprises conducting the polymerization reaction above the softening temperatures of the sticky polymers in the presence of about 0.3 to about 60 weight percent, based on the weight of the final product of an inlet particulate material having a mean particle size of from about 0.01 to about 10 micron meters whereby polymer agglomeration of the sticky polymers is maintained at a size suitable for continuously producing the sticky polymers.
摘要:
A catalyst useful for selectively converting a mixture of carbon monoxide and hydrogen to a mixture of lower alkanols consisting essentially of a mixture of molybdenum sulfide, an alkali metal compound and a tantalum compound.
摘要:
Alkali metal doped double perovskites containing manganese and at least one of cobalt, iron and nickel are useful in the oxidative coupling of alkane to higher hydrocarbons.
摘要:
A single crystal orthodontic bracket is disclosed which is provided with an outer protective layer of a polycrystalline material so as to provide fracture toughness of the orthodontic bracket.
摘要:
A composition comprising:(i) a homopolymer or copolymer of ethylene and one or more other alpha-olefins wherein the portion of the copolymer based on ethylene is at least about 60 percent by weight based on the weight of the copolymer, said polymers having a density of at least 0.940 gram per cubic centimeter;(ii) a homopolymer or copolymer of propylene and one or more other alpha-olefins wherein the portion of the copolymer based on propylene is at least about 60 percent by weight based on the weight of the copolymer; and(iii) an anhydride of an unsaturated aliphatic diacid.