Hydrolytically-stable dense star polyamine
AssigneeThe Dow Chemical Company
InventorsDonald A. Tomalia, James R. Dewald
Life of this patent
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Abstract
Dense star polyamines having terminal group densities greater than extended conventional star polyamines exhibit greater and more uniform reactivity than their corresponding extended conventional star polyamines. For example, a second generation, amine-terminated polyamine dense star polyamine prepared from tri(2-aminoethyl)amine and aziridine has 4.7.times.10.sup.-3 amine moieties per unit volume (cubic Angstrom units) in contrast to the 1.7.times.10.sup.-3 amine moieties per unit volume contained by an extended conventional star polyamine. Such dense star polyamines are useful as calibration standards, high efficiency proton scavengers and in making size selective membranes.
Claims21
A dense star polyamine having at least one core branch emanating from a core, each core branch having at least one terminal amine group provided that (1) the ratio of terminal amine groups to the branches emanating from the core is 2:1 or greater, (2) the density of terminal amine groups in the dense star polyamine is at least 1.5 times that of an extended conventional star polyamine having similar core and monomeric moieties and a comparable molecular weight and number of core branches wherein each of such branches of the conventional star polyamine bears only one terminal amine group, and (3) a molecular volume that is equal to or less than 80 percent of the molecular volume of said extended conventional star polyamine.
The dense star polyamine which is a dendrimer represented by the formula:
- ##EQU7## wherein .circle.I is a polyfunctional core, Z.sub.c is a functional group bonded to the core and an X group of the first generation, N.sub.c is the number of functional group bonded to the core, X.sup.i is a monofunctional tail of a repeating unit Y.sup.i of the i generation which is bonded to Y.sup.i and a Z group of the i-1 generation, Z.sup.i is a functional group bonded to Y.sup.i and an X group of the i+1 generation, N.sup.i is a number of at least 2 which corresponds to the multiplicity of the polyfunctional head of Y.sup.i, .pi. is the product function, N.sup.i-1 is a number of at least 2 which corresponds to the multiplicity of the polyfunctional head of Y.sup.i-1 wherein Y.sup.i-1 is a repeating unit of the Y.sup.i-1 generation, X.sup.t is the monofunctional tail of a repeating unit Y.sup.t of the terminal generation, Z.sup.t is a terminating group bonded to Y.sup.t, N.sup.t is zero or a number which corresponds to the number of Z.sup.t groups bonded to one Y.sup.t group, i represents a nunmber of a particular generation in a series from 1 to a number from 1 to t-1, provided that (1) all X.sup.i Y.sup.i (Z.sup.i).sub.N.spsb.i are the same within a generation and may be the same or different in different generations and (2) all X.sup.t Y.sup.t (Z.sup.t).sub.N.spsb.t of the terminal generation are the same.
Dependencies are inferred from the claim text.