초록 ▼

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

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.

대표청구항 ▼

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

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.