摘要:
Provided are a supported catalyst and a method for synthesizing a sucrose-6-ester. The supported catalyst includes an active functional component and an inorganic carrier, wherein the active functional component is a compound shown in formula (1), wherein n is a natural number greater than or equal to 2; R is an atom linked to a surface of the inorganic carrier; and one or two of R1, R2, and R3 is/are hydrocarbyl, and the rest are independently any one selected from the group consisting of oxygen, hydroxyl, hydrocarbyloxy, and acetoxy.
摘要:
The present disclosure provides a stannous salt complex catalyst and a method for producing L-lactide by using the same. The catalyst is obtained by reacting stannous salt and phosphite in a solvent, which can effectively inhibit the oxidation of divalent stannous ions to tetravalent tin ions, effectively reduce the conversion rate of meso-lactide, increase the yield of L-lactide, and obtain nearly white L-lactide. In the crude lactide produced after the depolymerization reaction, the content of L-lactide is more than or equal to 95 %; the content of meso-lactide is less than or equal to 3.8 %, while ensuring that the color of the residual liquid is close to milky white.
摘要:
Novel urethane-acrylate (UAC) Star monomers and polyurethane-acrylate (PUAC) aerogel polymers derived therefrom are described herein, along with other novel, related monomers and polymers. Also described herein are processes for preparing the UAC Star monomers, the PUAC aerogel polymers, and the other related monomers and polymers. The PUAC and related polymers herein are useful in various applications including in structural and thermal insulation.
摘要:
A method can include immortal ring-opening homopolymerisation of cyclic carbonates or cyclic esters in the presence of a catalytic system, or sequential two-step ring-opening block copolymerisation of one or more cyclic monomers selected from cyclic carbonates or cyclic esters in the presence of the catalytic system. The catalytic system can include a phenolate supported metallic complex. The catalytic system can also include an alcohol or a primary amine containing aliphatic and/or aromatic moieties. The alcohol or primary amine can be present in a molar ratio with respect to the metallic complex that is larger than 1.
摘要:
Novel urethane-acrylate (UAC) Star monomers and polyurethane-acrylate (PUAC) aerogel polymers derived therefrom are described herein, along with other novel, related monomers and polymers. Also described herein are processes for preparing the UAC Star monomers, the PUAC aerogel polymers, and the other related monomers and polymers. The PUAC and related polymers herein are useful in various applications including in structural and thermal insulation.
摘要:
The invention relates to an emulsifiable catalyst composition which comprises at least one of metal salts, metal complexes, and acids, and at least one amphiphilic compound which is a graft copolymer based on oils or diene homo-and copolymers that bear graft branches derived from olefinically unsaturated monomers, and an average, per molecule, of at least one cationic group or cationogenic group that forms cations when contacted with an acid, to a process for its preparation, and a method of use thereof as catalyst in aqueous coating compositions.
摘要:
Isocyanate prepolymer catalysts and processes for rapidly curing isocyanate prepolymers are disclosed herein. Substrates coated with the isocyanate prepolymers are treated with a drying agent and water, which combine to form a hydrated catalyst complex. Co-catalysts, such as organo tins, may be used to further enhance the curing rate.
摘要:
A catalyst composition for producing polyesters comprises: a) an organometallic compound obtained by reacting an orthoester or condensed orthoester of titanium, zirconium or aluminum, an alcohol containing at least two hydroxyl groups, a 2-hydroxy carboxylic acid and a base; and b) at least one compound comprising germanium, antimony or tin. Polyesters obtained by esterification reaction in the presence of the catalyst compositions according to the present invention exhibit improved melt properties and are particularly suitable for production of textile and commercial fibers, films and rigid packaging.
摘要:
Supported heterogeneous organotin catalysts of the formula X1, X2, or X3: wherein Z is a spacer group; Y is an insoluble phenyl-group containing copolymer; R1, R2, R3, R5, and R6 are independently selected from halogen, alkyl, alkylene, phenyl, vinyl, allyl, naphthyl, aralkyl, and Z; and R4 is alkyl, alkylene, phenyl, vinyl, allyl, naphthyl, or aralkyl.
摘要:
A process for the production of alkyltin alkoxides which comprises subjecting at least one alkyltin compound selected from among organotin compounds having tin-oxygen-tin linkages as the starting compound and a hydroxyl compound as the reactant to dehydration to obtain an alkyltin alkoxide corresponding to the starting compound and the reactant, characterized by continuously feeding the starting compound and the reactant into a reactor, discharging a water-containing low boiling point component from the reactor, and continuously withdrawing a reaction fluid containing an alkyltin alkoxide as the bottom from the reactor.