摘要:
An apparatus and method for spectral analysis of immiscible phases are disclosed. A flow cell for online absorption measurements of immiscible process phases can comprise: a body containing an inlet window and an outlet window in operable communication with a measurement instrument; and a series of partitions that divide the inside of the flow cell into three (3) or more vessels that have an inlet and an outlet, wherein the vessels are connected in series with one another. Optionally, the first vessel is equipped with a porous membrane to facilitate the separation of immiscible process phases.
摘要:
An apparatus and method for spectral analysis of immiscible phases are disclosed. A flow cell for online absorption measurements of immiscible process phases can comprise: a body containing an inlet window and an outlet window in operable communication with a measurement instrument; and a series of partitions that divide the inside of the flow cell into three (3) or more vessels that have an inlet and an outlet, wherein the vessels are connected in series with one another. Optionally, the first vessel is equipped with a porous membrane to facilitate the separation of immiscible process phases.
摘要:
A method is provided for making siloxane polycarbonate copolymers and blends of other polycarbonates with such copolymers wherein the copolymers and blends have excellent transparency and physical characteristic.
摘要:
Copolyestercarbonates comprising carbonate structural units derived from at least one dihydroxyaromatic compound, preferably bisphenol A, and ester units derived from a dihydroxyaromatic compound and a composition comprising at least one C36 dimer acid may be prepared by an interfacial phosgenation method conducted at a pH in the range of about 9-11. The copolyestercarbonates have properties which are often superior to those of corresponding polymers prepared, for example, from dodecanedioic acid.
摘要:
A method for purifying a crude acetone raw material containing low molecular weight impurities using three columns in sequence is disclosed. The method comprises the steps of feeding the crude acetone raw material into a first column; adding an alkaline reagent and an oxidative reagent into the first column; feeding the first bottom fraction to a second rectification column; optionally adding an alkaline reagent to the second column above the charge point of the bottom fraction; separating a purified acetone from the high molecular weight impurities and removing the purified acetone as a top fraction by distillation in the second column, thereby forming a second bottom fraction comprising an acetone mixture comprising high molecular weight impurities; feeding the second bottom fraction comprising the acetone mixture to a third rectification column; removing a top fraction from the third column; and returning the top fraction removed from the third column to the first column, wherein the second rectification column is operated at atmospheric pressure, and wherein the purified acetone has an acetaldehyde level of less than 5 ppm and a KT-Test time of greater than 11 hours, as measured by the SABIC KT-Test method.
摘要:
A method for the solventless synthesis of a phthalimide or phthalimide mixture is provided comprising contacting at least one amine reactant and at least one anhydride reactant in a solventless environment at a first temperature sufficient to allow the reactants to at least partially condense; and increasing the temperature to a second temperature sufficient to melt the reaction mixture, thereby allowing the reaction to go essentially to completion and form the reaction product.
摘要:
A method for purifying a crude acetone raw material containing low molecular weight impurities using three columns in sequence is disclosed. The method comprises the steps of feeding the crude acetone raw material into a first column; adding an alkaline reagent and an oxidative reagent into the first column; feeding the first bottom fraction to a second rectification column; optionally adding an alkaline reagent to the second column above the charge point of the bottom fraction; separating a purified acetone from the high molecular weight impurities and removing the purified acetone as a top fraction by distillation in the second column, thereby forming a second bottom fraction comprising an acetone mixture comprising high molecular weight impurities; feeding the second bottom fraction comprising the acetone mixture to a third rectification column; removing a top fraction from the third column; and returning the top fraction removed from the third column to the first column, wherein the second rectification column is operated at atmospheric pressure, and wherein the purified acetone has an acetaldehyde level of less than 5 ppm and a KT-Test time of greater than 11 hours, as measured by the SABIC KT-Test method.
摘要:
Diaminoalkyl quaternary ammonium salts are prepared by the reaction of alkyl halides with tertiary diamines having C.sub.2-20 primary alkyl radicals attached to nitrogen and an alkyl radical between the two nitrogen atoms in which at least three carbon atoms separate said nitrogen atoms. Said salts are preferably substantially free from corresponding diamines. They are useful as catalysts for interfacial polycarbonate preparation by the reaction of phosgene with at least one dihydroxyaromatic compound. Polycarbonate preparation using such catalysts is economical in phosgene consumption, is accompanied by a rapid conversion of chloroformate groups to desirable species and affords a product with a very low proportion of unreacted dihydroxyaromatic compound.
摘要:
A method for purifying a crude acetone raw material containing low molecular weight impurities using two columns is disclosed. Crude acetone raw material is fed into a first column; adding an alkaline reagent and an oxidative agent into the first column to form high molecular weight impurities; removing a top fraction from the first column by distillation to form bottom fraction containing an acetone mixture containing high molecular weight impurities; feeding the bottom fraction containing the acetone mixture obtained to a second rectification column at a charge point on the column; adding an alkaline reagent to the second column above the charge point of the bottom fraction fed; and separating a purified acetone from the high molecular weight impurities and removing the purified acetone as a top fraction by distillation in the second column, wherein the second rectification column is operated at atmospheric pressure.
摘要:
A method for purifying a crude acetone raw material containing low molecular weight impurities using two columns is disclosed. The method comprises the steps of feeding the crude acetone raw material into a first column; adding an alkaline reagent and an oxidative agent into the first column to form high molecular weight impurities; removing a top fraction from the first column by distillation to form bottom fraction comprising an acetone mixture comprising high molecular weight impurities; feeding the bottom fraction comprising the acetone mixture obtained to a second rectification column at a charge point on the column; adding an alkaline reagent to the second column above the charge point of the bottom fraction fed; and separating a purified acetone from the high molecular weight impurities and removing the purified acetone as a top fraction by distillation in the second column, wherein the second rectification column is operated at atmospheric pressure.