초록 ▼

New separation methods termed Enhanced Partitioning Fractionation (EPF) and High Osmotic Pressure Chromatography (HOPC) are described. The HOPC method involves passing large amounts of concentrated polymer solutions over porous material in a packed column. The concentration is high enough to allow f

New separation methods termed Enhanced Partitioning Fractionation (EPF) and High Osmotic Pressure Chromatography (HOPC) are described. The HOPC method involves passing large amounts of concentrated polymer solutions over porous material in a packed column. The concentration is high enough to allow for polymer chain overlap and to generate high osmotic pressures with respect to the porous material. The resulting high osmotic pressure causes increased separation of the polymer sample based on molecular size. The higher molecular weight components are concentrated in the initial fractions of eluent collected, whereas lower molecular weight components are concentrated in later fractions. The molecular weight of each fraction decreases with each successive fraction of eluent. The method is applicable to a wide variety of polymers and provides significant performance advantages to conventional preparative scale GPC. EPF is not a chromatographic procedure, but allows for fractionation of concentrated polymer solutions that generate high osmotic pressures in contact with porous material.

대표청구항 ▼

A method for fractionating polymers based on molecular size comprising the steps of: (A) providing a solution of polymer dissolved in a first solvent, said polymer having an initial polydispersity index greater than 1.000 and including higher and lower molecular weight polymer components, said polym

A method for fractionating polymers based on molecular size comprising the steps of: (A) providing a solution of polymer dissolved in a first solvent, said polymer having an initial polydispersity index greater than 1.000 and including higher and lower molecular weight polymer components, said polymer being dissolved in said first solvent at a concentration about equal to or greater than an overlap concentration, c*, of said polymer but less than a concentration at which said solution is no longer fluid, (B) passing said solution as a mobile phase through a chromatographic matrix to generate an eluent, said matrix including a porous material imbibed with a second solvent, said second solvent imbibed in said porous material acting as a stationary phase in communication with said mobile phase, said porous material having pore openings of a dimension on the order of a molecular size of said polymer that allows said lower and higher molecular weight polymer components to migrate selectively between said mobile phase and said stationary phase to effect size-based partitioning of said polymer, whereby said migration is enhanced by a relatively high osmotic pressure generated because said concentration is about equal to or greater than said overlap concentration, c*, and (C) eluting said polymer from said porous material.