Dense star polymers having two dimensional molecular diameter
First Claim
1. A dense 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 branches emanating from the core is 2:
- 1 or greater, (2) the density of terminal groups in the dense star polymer is at least 1.5 times that of an extended conventional star polymer having similar core and monomeric moieties and a comparable molecular weight and number of core branches wherein each of such branches of the extended conventional star polymer bears only one terminal group, (3) a molecular volume that is equal to or less than 80 percent of the molecular volume of said extended conventional star polymer, and (4) the two-dimensional molecular diameter of the dense star polymer is in the range from about 12 to about 2000 Angstroms.
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Abstract
Dense star polymers having terminal group densities greater than conventional extended star polymers exhibit greater and more uniform reactivity than their corresponding conventional star polymers. For example, a third generation, hydroxy-terminated polyether dense star polymer can be prepared from pentaerythrityltetrabromide and 4-hydroxymethyl-2,6,7-trioxabicyclo[2.2.2]-octane which has a molecular volume less than 80 percent of the volume of a conventional extended star polymer made from similar materials. Such dense star polymers are useful as demulsifiers for oil/water emulsions, wet strength agents in the manufacture of paper, proton scavengers, calibration standards for electron microscopy, and agents for modifying viscosity in aqueous formulations such as paints.
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Citations
17 Claims
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1. A dense 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 branches emanating from the core is 2:
- 1 or greater, (2) the density of terminal groups in the dense star polymer is at least 1.5 times that of an extended conventional star polymer having similar core and monomeric moieties and a comparable molecular weight and number of core branches wherein each of such branches of the extended conventional star polymer bears only one terminal group, (3) a molecular volume that is equal to or less than 80 percent of the molecular volume of said extended conventional star polymer, and (4) the two-dimensional molecular diameter of the dense star polymer is in the range from about 12 to about 2000 Angstroms.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 12)
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8. A dense star polymer which is a dendrimer represented by the formula:
wherein ○
I is a polyfunctional core, Zc is a functional group bonded to the core and a X group of the first generation, Nc is the number of functional group bonded to the core, Xi is a monofunctional tail of a repeating unit Yi of the i generation which is bonded to Yi and a Z group of the i-1 generation, Zi is a functional group bonded to Yi and a X group of the i+1 generation, Ni is a number of at least 2 which corresponds to the multiplicity of the polyfunctional head of Yi, is the product function, Ni-1 is a number of at least 2 which corresponds to the multiplicity of the polyfunctional head of Yi-1 wherein Yi-1 is a repeating unit of the Yi-1 generation, Xt is the monofunctional tail of a repeating unit Yt of the terminal generation, Zt is a terminating group bonded to Yt, Nt is zero or a number which corresponds to the number of Zt groups bonded to one Yt group, i represents a number of a particular generation in a series from 1 to a number from 1 to t-1, provided that (1) all Xi Yi (Zi)N i are the same within a generation and may be the same or different in different generations and (2) all Xt Yt (Zt)N t of the terminal generation are the same.- View Dependent Claims (9, 10, 11, 13, 14, 15, 16, 17)
Specification