Dense star polymers and a process for producing dense star polymers

Claim 2

A star polymer having at least one core branch emanating from a core, each core branch having at least one terminal group provided that (1) the ratio of terminal groups to the core branches is greater than 1:1, (2) the density of terminal groups per unit volume in the polymer is at least 1.5 times that of a conventional star polymer having similar core and monomeric moieties and a comparable molecular weight and number of core branches, each of such branches of the conventional star polymer bearing only one terminal group, and (3) a molecular volume that is no more than 60 percent of the molecular volume of said conventional star polymer.

Claim 3

The star polymer of Claim 1 having (1) at least 2 core branches per core, (2) a terminal group density at least 5 times that of the corresponding conventional star polymer, (3) a molecular volume that is no more than 50 percent of the volume of the conventional star polymer, and (4) a ratio of terminal groups to core branches is 2:1 or more.

Claim 4

The polymer of Claim 1 which is a den - drimer having a polyvalent core that is covalently bonded to at least 1 ordered dendritic branch which extends to two generations such that each dendritic branch has at least four terminal groups and a symmetrical structure.

Claim 5

The polymer of Claim 1 wherein the dendritic branches contain amidoamine linkages.

Claim 6

The polymer of Claim 1 wherein the core is derived from a nucleophilic compound and the branches are polyamidoamines wherein the terminal groups are primary amine groups.

Claim 7

The polymer of Claim 1 wherein the nucleophilic core is derived from a core compound having a plurality of active hydrogens capable of undergoing a Michael's addition reaction with an ethylenically unsaturated group.

Claim 8

The polymer of Claim 5 wherein the nucleophilic compound is an amine having a plurality of amine hydrogens.

Claim 9

The polymer of Claim 5 wherein the branches are polyamidoamine which is derived from the reaction of an alkyl ester of an a,p-ethylenically unsaturated carboxylic acid or an α,β-ethylenically unsaturated amide and an alkylene polyamine or a polyalkylene polyamine.

Claim 10

The polymer of Claim 8 wherein the nucleophilic compound is ammonia, the ester is methyl acrylate and the polyamine is ethylenediamine.

Claim 11

A process for producing the dense star polymer of Claim 1 comprising the steps of: (A) contacting (1) a core compound having at least one nucleophilic or one electrophilic moiety (N/E moieties) with (2) an excess of a first organic coreactant having (a) one core reactive moiety which is reactive with the N/E moieties of the core compound, and (b)an N/E moiety which does not react with the N/E moiety of the core under conditions sufficient to form a core adduct wherein each N/E moiety of the core compound has reacted with the core reactive moiety of a different molecule of the first coreactant; (B) contacting (1) the core adduct having at least twice the number of N/E moieties as the core compound with (2) an excess of a second organic coreactant having (a) one adduct. reactive moiety which will react with the N/E moieties of the core adduct and (b) a N/E moiety which does not react with the N/E moiety of the core adduct under conditions sufficient to form a first generation adduct having a number of N/E moieties that are at least twice the number of N/E moieties in the core adduct; and (C) contacting the first generation adduct with an excess of a third organic coreactant having one moiety that is reactive with the N/E moieties of the first generation adduct and an N/E moiety that does not react with the N/E moieties of the first generation adduct under conditions sufficient to form a second generation dendrimer, wherein the first coreactant differs from the second coreactant, and the second coreactant differs from the third coreactant, but the first and third coreactants may be the same or different compounds. ,