摘要:
The present invention relates to an improved, fully-integrated continuous process of enhanced process operability for manufacturing copolyether glycols having enhanced physical properties by polymerization of a reaction mixture comprising tetrahydrofuran and at least one alkylene oxide in the presence of an acid catalyst and at least one compound containing reactive hydrogen atoms. The copolyether glycols manufactured by the present process have enhanced physical properties of increased alkylene oxide incorporation, average molecular weight and polydispersity, as well as reduced crystallinity, color, oligomeric cyclic ether content, and linear oligomer having an average molecular weight of up to about 400 dalton content.
摘要:
An oxytetramethylene glycol copolymer which is obtained by copolymerizing tetrahydrofuran with neopentyl glycol and has specific values of number-average molecular weight (Mn), molecular-weight distribution (Mn/Mw), degree of total neopentyl glycol copolymerization (Nw), and degree of partial neopentyl glycol copolymerization (Nh); a process for producing the copolymer; and a method of purifying the oxytetramethylene glycol copolymer contained in a copolymerization reaction mixture comprising the copolymer and an unreacted diol which comprises adding fresh tetrahydrofuran to the mixture in an amount at least the same as that of the unreacted diol by weight and distilling off the unreacted diol together with the tetrahydrofuran.
摘要:
The invention relates to a method for the depolymerization of mixtures that contain mono- and/or diesters of polytetrahydrofurane in the presence of an acid catalyst and of a C1 to C3 alcohol at temperatures of 80 to 200 °C and a pressure of 0.05 to 0.5 MPa, the molar ratio of the C1 to C3 alcohol to the carboxyl groups contained in the mixture being greater than 1.
摘要:
The present invention herein provides a process for making an aminobenzoate ester of an alcoholic organic compound. In one aspect, there is provided a process for making an aminobenzoate ester comprising the steps of: (a) providing a reaction mixture comprising an alkyl aminobenzoate an alcohol reagent and a suitable transesterification catalyst; (b) introducing an auxilliary alcohol to the reaction mixture; and (c) exposing the reaction mixture to conditions effective to provide an end-product mixture comprising the aminobenzoate ester.
摘要:
This application is directed to fluorinated oxetane monomers and methods for making the monomers. The mono-substituted fluorinated oxetane monomers having fluorinated alkoxymethylene side-chains are prepared in high yield by the reaction of fluorinated alkoxides with either 3-halomethyl-3-methyloxetane premonomers or aryl sulfonate derivatives of 3-hydroxymethyl-3-methyloxetane premonomers. Preparation of a mono-substituted 3-bromomethyl-3-methyloxetane premonomer via a simple, high yield process amenable to commercial scale-up is also disclosed. The fluorinated oxetane monomers are useful for the production of fluorinated prepolymers and elastomers which exhibit an improved contact angle for drops of water on a fluorinated oxetane elastomer as compared to a TeflonTM surface.
摘要:
A method for applying a reactive epoxy containing coating to a substrate, said method comprising subjecting said substrate to a plasma discharge in the presence of a compound of formula (I) or (IA) where R?1 or R1a¿ is an optionally substituted hydrocarbyl group or heterocyclic group; R2 is an optionally substituted straight or branched alkylene chain; and Y is oxygen or a bond. Surfaces obtained in this way may subsequently be derivatised as desired, or adhered to other surfaces.
摘要:
The invention relates to a method for producing monoesters or diesters of polytetrahydrofuran or of tetrahydrofuran copolymers by polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer on an acid catalyst. According to the invention, the polymerization reactor is started up with a mixture consisting of polytetrahydrofuran, the monoesters or diesters of the polytetrahydrofuran and/or of the THF copolymers, tetrahydrofuran, optionally, a comonomer and of at least one carboxylic acid and/or of a carboxylic acid anhydride.
摘要:
The invention relates to a method for the single-step production of polyoxyalkylene glycols by the copolymerisation of THF and alpha, omega diols in the presence of a heteropoly acid. Said method is characterised in that the content of organically bonded nitrogen in the alpha, omega diol is less than 15 ppm.
摘要:
A polyoxytetramethylene glycol (PTMG) with improved heat resistance and low-viscosity characteristics which has the following properties (1) to (4): (1) the number-average molecular weight is 500 to 3,000; (2) the molecular-weight distribution which is the ratio of the weight-average molecular weight Mw to the number-average molecular weight Mn, Mw/Mn, is 1.8 or less; (3) the content of PTMG molecules having a molecular weight at least 6 times the number-average molecular weight is 2 to 5 wt.% based on the total amount of all the PTMG molecules; and (4) the content of heteropolyacids is 10 to 900 ppb by weight.