Star Copolymers
Star copolymers are copolymers with several long chain branches. (RDC 10/13/2010)
“Dendrimers are described as globular, nano-scale macromolecules consisting of two or more tree-like dendrons., emanating from a single central atom or atomic group called the core. They are comprised of branch cells that are the main building blocks of dendritic structures, that is, three-dimensional analogues of repeat units in classical linear polymers, that must contain at least one branch juncture, and that are organized in mathematically precise architectural arrangements, that give rise to a series of regular radially concentric layers. called generations (G) around the core. Dendrimers must contain at least three different types of branch cells including a core, interior cells, and surface or exterior cells. “
” Dendrons are the smallest constitutive elements of a dendrimer that have the same architectural arrangement as the dendrimer itself, but which emanate from a single trunk or branch, which may end with a potentially reactive, or a potentially inert functional group called by those skilled in this particular art, the focal group. “
On the other hand,hyperbranched polymers are random highly branched macromolecules usually obtained from a "one-shot" polymerization reaction of an ABw where A and B represent mutually reactive functional groups of the monomer. They are usually different from dendrons, in that, hyperbranched macromolecules are considerably more architecturally variable in their structure, have a lower degree of branching, and as materials, usually have a high degree of polydispersity, in that, not all hyperbranched macromolecules of the same hyperbranched polymer are of the same molecular weight or chain length.
[Camblee, Kim and Skinner, US Patent 7,384,546 (6/10/2008)]
Note: These authors referred to Polymer Preprints. Division of Polymer Chemistry, American Chemical Society. Volume 39, Number 1, Pages 473 to 474, (March, 1998).
Block Copolymers
Copolymers
Dendrimer (Star Copolymer) Drug Delivery
Polymers /Resins
Synthesizing Star Copolymers
Recent US Patents
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8/10/2010
7,771,521
Hyperbranched polyimide-based hybrid material
Yamada and Suzuki of the Nagoya Institute of Technology, Japan has developed a hyperbranched polyamic acid having hydroxyl groups or alkoxy end groups and alkoxide chains.
8/3/2010
7,767,091
Method for encapsulating pollutants from water using modified dendrimeric polymers
Paleos et al of the The National Center for Scientific Research "Demokritos" in Greece, developed a dendritic copolymer which will remove water contaminants at parts per billion and below. The polymer consists of iminio branches extended with lipophilic hydrocarbons. These branches become molecular claws which remove pollutants such as benzene and polyaromatic compounds to less than 5 parts per billion. (RDV 10/13/2010)
6/10/2008
7,384,546
Multi-layered macromolecules and methods for their use
Campbell, Kim and Skinner have developed multilayer polymer structures based on base star copolymers attached to solid particles, and then attached to other star copolymers using silane coupling agents. (RDC 10/13/2010)