Abstract: Hexasubstituted guanidinium chlorides are prepared by a method which affords them in high yield as aqueous solutions, optionally also containing alkali metal chlorides. The solutions may be employed as sources of hexasubstituted guanidinium salts useful as phase transfer catalysts for the reaction of alkali metal salts of dihydroxyaromatic compounds with substituted imides to form polyetherimides or their intermediates.

Abstract: A method of preparing a polycarbonate comprising the steps of:a) charging at least one dihydroxy compound, an inert solvent, water, caustic, carbonyl halide, and catalyst to a vessel, and maintaining the pH of the reaction mixture between about 4 and about 12 during charging; andb) within an interval of between 0 and about 90% of the total carbonyl halide addition to the vessel, activating a reaction system that produces monofunctional aromatic chloroformates (MAC) and introducing the MAC to the vessel within the interval of 0 to about 90% of the total carbonyl halide addition to the vessel; where the MAC reaction system is coupled with the vessel, and where means are provided for delivery of the MAC from the reaction system to the vessel.

Abstract: Hexasubstituted guanidinium chlorides are prepared by a method which affords them in high yield as aqueous solutions, optionally also containing alkali metal chlorides. The solutions may be employed as sources of hexasubstituted guanidinium salts useful as phase transfer catalysts and the reaction of alkali metal salts of dihydroxyaromatic compounds with substituted imides to form polyetherimides or their intermediates.

Abstract: 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.

Abstract: An adsorption process uses a non-ion-exchangeable adsorbent polymeric resin of a monoethylenically unsaturated monomer such as styrene and a polyvinylidene monomer such as divinylbenzene for the adsorption of organic bases, such amines, amine salts and guanidinium salts, from high ionic strength aqueous solutions. Desorption may be employed for the recovery of said organic bases, and said adsorbent resin may be regenerated.