Maro Publications

Star Copolymers

From 05/30/2014 through 9/2/2013

Maro Encyclopedia




Patent Abstracts

Patent Titles




Patent Titles


26.  8,552,141 
Hyper-branched polyester for use in CPT toner and method of preparing the same 


25. 8,546,493 
Multi-armed, monofunctional, and hydrolytically stable derivatives of poly(ethylene glycol) and related polymers for modification of surfaces and molecules 


24. 8,536,280 
Star polymer and coupling agent for anionic polymerization 


23. 8,530,568 
Flowable polyamides with hyperbranched polyesters/polycarbonates 


22. 8,524,858 
Preparation of hyperbranched poly(triazole)s by in situ click polymerization and adhesive containing the same


22. 8,487,061 
Star hydrocarbon polymer, process for making, and a polymer blend composition having same 

21. 8,487,059 
Synthesis of dendritic polyolefins by metathesis insertion polymerization 

20. 8,486,135 
Implantable medical devices fabricated from branched polymers 


19. 8,481,650 
Process for production of polymers having functional groups, and star polymers obtained thereby 


18. 8,476,386 
Hyperbranched polymers and their applications 

17. 8,476,373 
Branched and star-branched styrene polymers, telomers, and adducts, their synthesis, their bromination, and their uses 


16. 8,466,241 
Method for producing highly branched polymer 


15.  8,445,577 
Amphiphilic multi-arm copolymers and nanomaterials derived therefrom 

14. 8,445,576 
Continuous process for preparing polyalkylene arylates with hyperbranched polyesters and/or polycarbonates 

13. 8,445,528 
Dendrimer conjugates 

12. 8,445,024 
Preparations containing hyperbranched polymers 


11. 8,441,005 
Light-emitting material comprising photoactive group-bonded polysilsesquioxane having a ladder structure, thin film using the same and organic electronic device comprising the same  

10. 8,440,816 
Branched polymers 

9. 8,440,787 
Hydroxyapatite-targeting multiarm polymers and conjugates made therefrom 


8. 8,436,118 
Synthesis of acylarylenes and hyperbranched poly(aclarylene)s by metal-free cyclotrimerization of alkynes 

7. 8,436,103 
Star polymer and method of producing the same 


6. 8,420,231 
Iridium phosphorescent dendrimer, method of preparing the same and electroluminescent device including the iridium phosphorescent dendrimer 


5, 8,394,878 
Hyperbranched organic modifier, method of preparing thereof and organo-modified clay using the same 

4. 8,394,500 
Compositions based on hyperbranched condensation polymers and novel hyperbranched condensation polymers 

Multi-arm polymer prodrugs 


2. 8,389,639 
Modified hyper-branched polymer and proton exchange membrane applied with the same, and method for manufacturing the proton exchange membrane 


1. 8,378,049 
Production and use of highly functional, highly branched or hyperbranched polylysines 


Patent Abstracts

4. 8,445,577 
 Amphiphilic multi-arm copolymers and nanomaterials derived therefrom

Lin and Pang of Ohio State University have eveloped amphiphilic multi-arm copolymers consisting of copolymer cores connected amphiphilic block copolymer arms.  Each block copolymer arm is substituted and includes at least one hydrophilic homopolymer subunit and at least one hydrophobic homopolymer subunit.  The core can be a cyclodextrin such as a beta-cyclodextrin (.beta.-CD).  Hydroxyl groups can be points of substitution leading to amphiphilic block copolymer arms.  The homopolymer subunits can include about 1 to 1,000,000 repeating units.  Any suitable polymerization method can be used including living polymerization, atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain-transfer (RAFT) polymerization, anionic polymerization, or coordination-insertion ring-opening polymerization.  [Star Copolymers, US Patent 8,445,577 (5/21/2013)]

3. 8,394,878 
Hyperbranched organic modifier, method of preparing thereof and organo-modified clay using the same 

Clay used in preparing polymer-clay nanocomposites has a layered-structure in which silicate plates are layered on a nanoscale by van der Waals' force. A polymer-clay nanocomposite makes the layered silicate structure exfoliated. This allows silicate to disperse uniformly on a nanoscale in polymer resins, so that the polymer resin can have better mechanical properties than conventional polymer resins and can achieve new properties such as gas shielding and thermal resistance that are not seen in conventional resins. However, the clay used in a nanocomposite is itself hydrophilic and it is mainly acquired by treating natural montmorillonite with a metal cation. Further, there are difficulties in exfoliation and dispersion of the layered-structure into hydrophobic polymer resins because strong van der Waals' force acts between layers of silicate plates.

Kim et al of Cheil Industries, South Korea, developed a hyperbranched polymer organic modifier which is stably dispersed in water and polar organic solvent. They reacted (a) a tertiary amine compound having at least two terminal hydroxyl groups with (b) at least one multifunctional monomer having at least two terminal functional groups capable of reacting with the hydroxyl groups.  The result is a hyperbranched organic modifier with a number average molecular weight of about 200 to about 30,000, about 5 to about 300 hydroxyl groups per polymer chain and about 0 to about 100 carbonyl groups of per polymer chain.  (RDC 4/3/2013)

2. 8,193,294 
Networks containing perfluorocarbon organosilicon hyperbranched polymers
Hu et al of the Michigan Molecular Institute, Michigan, developed hyperbranched copolymer networks containing hyperbranched copolymers that have perfluorocarbon and organosilicon entities that have high hydrophobicity, or high oleophobicity, or high thermal stability, or good adhesion to substrates, or any combinations thereof. This invention provides a further desirable combination of properties that include solubility before crosslinking, chemical resistance, and easy processibility. The copolymers may be crosslinked with a variety of crosslinking agents to give either rigid or elastomeric networks. (RDC 6/27/2012)

1. 8,193,286 
Acrylic star polymer
Matsumoto and Nakamura of Nippon Soda, Japan, producedd a star polymer having a controlled ratio of a weight average molecular weight of the star polymer to a number average molecular weight of the star polymer, by anionically polymerizing a (meth)acrylic ester having an alicyclic skeleton and a lactone ring in the presence of an anionic polymerization initiator to synthesize an arm polymer, reacting the arm polymer with a polyfunctional coupling agent, and reacting with an anionic polymerizable monomer. (RDC 6/27/2012)



1. A star shaped polymer is a polymeric structure in which several chains emanate from a single junction point known as the core. The control offered by anionic polymerization makes it a very popular pathway to synthesize molecules with such complex geometry. It allows quantitative studies of the degree of branching of the polymer on the overall properties of the substance.

One of the first pathways explored was the use of a multifunctional initiator , but it was limited by the insolubility of such compounds and there was no control over the reactivity of each branch. A second, more efficient way was proposed - the addition of a multifunctional electrophilic terminator at the end of the polymerization of a linear polymer. This is analogous to the convergent synthesis of dendrimers, and is efficient as long as the stoichiometry between the terminating agent and the starting monomers are maintained.

The third route is through the addition of small amounts of cross linking agents to the polymeric precursor (for example, addition of divinyl benzene to polystyryl lithium). There are three prime reactions that take place:

 The crossover of the polystyryl chain to divinylbenzene

 The block copolymerization of divinylbenzene

 The reaction of the pendant vinyl groups of divinyl benzene with linear polystyryl branches

The uniformity in the structure is a function of the rate of the crossover reaction compared to the other two reactions. The number of branches of the star molecules cannot be precisely predicted, as it is a complex function of the reaction variables.  For example, the amount of divinyl benzene added in the above pathway, compared to the number of active chains, is a key factor governing the overall degree of branching of the polymer.

The method is widely used for the synthesis of star shaped polystyrene with divinyl benzene with low molecular weight distributions.  Star shaped polymethyl methacrylate was similarly synthesized using ethylene glycol dimetthacrylate as a crosslinker.  The molecular weights obtained are comparatively high (~40kDa), which is thought to be necessary to avoid the gelation due to inter core reactions.  The protection of the core groups by the branches gave such polymers the name "porcupine polymers".

(Wikipedia, Star Polymers, 6/28/2012)


Bookmark this page to follow future developments!.
(RDC 7/16/2012)


Roger D. Corneliussen

Maro Polymer Links
Tel: 610 363 9920
Fax: 610 363 9921


Copyright 2013 by Roger D. Corneliussen.
No part of this transmission is to be duplicated in any manner or forwarded by electronic mail without the express written permission of Roger D. Corneliussen

* Date of latest addition; date of first entry is 10/8/2013.