摘要:
A method for the purification of aromatic polyether polymers prepared by a halide displacement polymerization process comprises adsorbing the catalyst with an alkali metal halide to form an adsorbent component and then removing the adsorbent component. Mixtures resulting from this method are also discussed.
摘要:
A method for the purification of aromatic polyether polymers prepared by a halide displacement polymerization process comprises adsorbing the catalyst with an alkali metal halide to form an adsorbent component and then removing the adsorbent component. Mixtures resulting from this method are also discussed.
摘要:
A method for purifying an oxydiphthalic anhydride comprises diluting a first mixture comprising an oxydiphthalic anhydride, a solvent, a catalyst, and an inorganic salt with a solvent, to provide a second mixture having a solids content of 10 to 30 percent based on total weight of the second mixture; filtering and washing the solids of the second mixture at a temperature below the crystallization point temperature of the oxydiphthalic anhydride to provide a third mixture; hydrolyzing the third mixture by adding water and a water-soluble acid to form a fourth mixture; heating the fourth mixture; then cooling to provide a solid-liquid mixture, optionally decanting a portion of the liquid, rediluting the remaining solid-liquid mixture, then filtering to provide a solid component; washing the solid component with water to provide a fifth mixture of oxydiphthalic tetraacid and water; ring closing the oxydiphthalic tetraacid to provide oxydiphthalic anhydride, and filtering the oxydiphthalic anhydride.
摘要:
a method for preparing an oxydiphthalic anhydride comprises contacting, under reactive and substantially anhydrous conditions in a reactor, at least one halophthalic anhydride containing more than 250 ppm chlorophthalide impurity with a carbonate of the formula M2CO3, wherein M is an alkali metal, in the presence of a catalytic proportion of at least one phase transfer catalyst selected from the group consisting of hexaalkylguanidinium halides and alpha,omega-bis(pentaalkylguanidinium)alkane salts, phosphonium salts, phosphazenium salts, pyridinium salts, phosphazenium salts, ammonium salts, and combinations thereof. The phase transfer catalyst is present in a sufficient amount to prepare the oxydiphthalic anhydride when the chlorophthalide is present in an amount that is more than 250 ppm, and the oxydiphthalic anhydride is produced in a yield, based on the carbonate, of at least 70%.
摘要:
A method for purifying an oxydiphthalic anhydride comprises diluting a first mixture comprising an oxydiphthalic anhydride, a solvent, a catalyst, and an inorganic salt with a solvent, to provide a second mixture having a solids content of 10 to 30 percent based on total weight of the second mixture; filtering and washing the solids of the second mixture at a temperature below the crystallization point temperature of the oxydiphthalic anhydride to provide a third mixture; hydrolyzing the third mixture by adding water and a water-soluble acid to form a fourth mixture; heating the fourth mixture; then cooling to provide a solid-liquid mixture, optionally decanting a portion of the liquid, rediluting the remaining solid-liquid mixture, then filtering to provide a solid component; washing the solid component with water to provide a fifth mixture of oxydiphthalic tetraacid and water; ring closing the oxydiphthalic tetraacid to provide oxydiphthalic anhydride, and filtering the oxydiphthalic anhydride.
摘要:
A method for the purification of aromatic polyether polymers prepared by a halide displacement polymerization process comprises adsorbing the catalyst with an alkali metal halide to form an adsorbent component and then removing the adsorbent component. Mixtures resulting from this method are also discussed.
摘要:
A method for the purification of aromatic polyether polymers prepared by a halide displacement polymerization process comprises adsorbing the catalyst with an alkali metal halide to form an adsorbent component and then removing the adsorbent component. Mixtures resulting from this method are also discussed.
摘要:
A method for preparing an oxydiphthalic anhydride comprises contacting, under reactive and substantially anhydrous conditions in a reactor, at least one halophthalic anhydride containing more than 250 ppm chlorophthalide impurity with a carbonate of the formula M2CO3, wherein M is an alkali metal, in the presence of a catalytic proportion of at least one phase transfer catalyst selected from the group consisting of hexaalkylguanidinium halides and alpha,omega-bis(pentaalkylguanidinium)alkane salts, phosphonium salts, phosphazenium salts, pyridinium salts, phosphazenium salts, ammonium salts, and combinations thereof. The phase transfer catalyst is present in a sufficient amount to prepare the oxydiphthalic anhydride when the chlorophthalide is present in an amount that is more than 250 ppm, and the oxydiphthalic anhydride is produced in a yield, based on the carbonate, of at least 70%.