摘要:
A cross-linked polymer-supported 4-(N-benzyl-N-methylamino) pyridine material and process for its preparation in high yield and having effective physical and catalytic properties. The polymer-supported catalyst is characterized by the suspension copolymerization of an organic phase containing the corresponding vinyl-substituted pyridine monomer, a styrene monomer, and a suitable cross-linking agent and free radical-generating catalyst in the presence of an aqueous phase containing a cellulose ether derivative as the stabilizing agent. The catalyst is further characterized by its yield in excess of 90% by weight and by its predominant and generally spherical and smooth bead form and substantially uniform size that is efficiently hard and durable and possesses sufficient catalytic activity for effective use in acylation, alkylation or other related reactions.
摘要:
A cross-linked polymer-supported 4-(N-benzyl-N-methylamino) pyridine material and process for its preparation in high yield and having effective physical and catalytic properties. The polymer-supported catalyst is characterizd by the suspension copolymerization of an organic phase containing the corresponding vinyl-substituted pyridine monomer, a styrene monomer, and a suitable cross-linking agent and free radical-generating catalyst in the presence of an aqueous phase containing a cellulose ether derivative as the stabilizing agent. The catalyst is further characterized by its yield in excess of 90% by weight and by its predominant and generally spherical and smooth bead form and substantially uniform size that is efficiently hard and durable and possesses sufficient catalytic activity for effective use in acylation, alkylation or other related reactions.
摘要:
A cross-linked polymer-supported 4-(N-benzyl-N-methylamino) pyridine material and process for its preparation in high yield and having effective physical and catalytic properties. The polymer supported catalyst is characterized by the suspension copolymerization of an organic phase containing the corresponding vinyl-substituted pyridine monomer, a styrene monomer, and a suitable cross-linking agent and free radical-generating catalyst in the presence of an aqueous phase containing a cellulose ether derivative as the stabilizing agent. A purified acid salt of the vinyl-substituted pyridine monomer useful in polymerizations and stable for storage as either a solid or an aqueous solution.
摘要:
Described are preferred monomers including a vinylbenzyl moiety N-bonded to an alkylaminopyridinyl or pyridylimidazolyl function. Also described are preferred acid salts of such monomers. Additionally, preferred processes involving and resins formed from these preferred monomers are described. The preferred resins are highly selective for valuable heavy metal ions such as copper and demonstrate superior iron rejection values.
摘要:
A cross-linked polymer-supported 4-(N-benzyl-N-methylamino) pyridine material and process for its preparation in high yield and having effective physical and catalytic properties. The polymer-supported catalyst is characterized by the suspension copolymerization of an organic phase containing the corresponding vinyl-substituted pyridine monomer, a styrene monomer, and a suitable cross-linking agent and free radical-generating catalyst in the presence of an aqueous phase containing a cellulose ether derivative as the stabilizing agent. A purified acid salt of the vinyl-substituted pyridine monomer useful in polymerizations and stable for storage as either a solid or an aqueous solution.
摘要:
A cross-linked polymer-supported 4-(N-benzyl-N-methylamino) pyridine material and process for its preparation in high yield and having effective physical and catalytic properties. The polymer-supported catalyst is characterized by the suspension copolymerization of an organic phase containing the corresponding vinyl-substituted pyridine monomer, a styrene monomer, and a suitable cross-linking agent and free radical-generating catalyst in the presence of an aqueous phase containing a cellulose ether derivative as the stabilizing agent. A purified acid salt of the vinyl-substituted pyridine monomer useful in polymerizations and stable for storage as either a solid or an aqueous solution.
摘要:
Described are preferred monomers including a vinylbenzyl moiety N-bonded to an alkylaminopyridinyl or pyridylimidazolyl function. Also described are preferred acid salts of such monomers. Additionally, preferred processes involving and resins formed from these preferred monomers are described. The preferred resins are highly selective for valuable heavy metal ions such as copper and demonstrate superior iron rejection values.
摘要:
Described are preferred processes for recovering citric acid from a medium in which it is contained. The citric acid is recovered both effectively and in a form which is readily purifiable. In one preferred process, the citric acid-containing medium is contacted with a solid-phase free base resin having tertiary amine groups to adsorb the citric acid. The citric acid is then desorbed by displacement with a stronger acid, and a citric acid-containing fraction is collected substantially free from contamination by the stronger acid. In another preferred process, a citric acid-containing medium is contacted with a solid-phase divinylbenzene-crosslinked polymer having pyridine or aliphatic tertiary amine functions to adsorb citric acid, the contacting being at a temperature below about 40.degree. C. Adsorbed citric acid is then desorbed with hot H.sub.2 O at a temperature of at least about 75.degree. C. Unnecessary impurities such as those arising from the use of organic solvent or throughput inorganic acid desorbents are thereby avoided while at the same time achieving a commercially attractive recovery of the citric acid. Additional preferred modes and process features are also described.
摘要:
Described are anion-exchange materials having extraordinarily high affinity for plutonium anions such as plutonium (IV), and technetium anions such as pertechnetate. Preferred inventive resins are highly divinylbenzene cross-linked polyvinylpyridine resins exhibiting a macroreticular bead form, which have been quaternized to contain a substantial amount of 1-alkyl-pyridinium groups wherein the alkyl group has 4 to 8 carbon atoms. The inventive resins can be used in preferred processes for recovering plutonium and/or technetium anions from aqueous mediums, for example nuclear waste streams or groundwater related to civilian or defense-related nuclear operations.
摘要:
Described are anion-exchange materials having extraordinarily high affinity for plutonium anions such as plutonium (IV), and technetium anions such as pertechnetate. Preferred inventive resins are highly divinylbenzene-crosslinked polyvinylpyridine resins exhibiting a macroreticular bead form, which have been quaternized to contain a substantial amount of 1-alkyl-pyridinium groups wherein the alkyl group has 4 to 8 carbon atoms. The inventive resins can be used in preferred processes for recovering plutonium and/or technetium anions from aqueous mediums, for example nuclear waste streams or groundwater related to civilian or defense-related nuclear operations.