Living radical polymerization hyperbranched polymers

As a unique method of controlled/living radical polymerization, ATRP has had a tremendous impact on the synthesis of macromolecules with well-defined compositions, architectures, and functionalities, including star- and comb-like polymers as well as branched, hyperbranched, dendritic, network, cyclic type structures and so forth. 

The development of PPE synthetic chemistry makes the synthesis of PPEs with various structures possible. Recently, PPE-based polymers with different topological structures including linear random copolymers, block copolymers, star polymers, miktoarm polymers, and brush and hyperbranched polymers have been synthesized. Among them, linear homopolymers or random copolymers of PPEs are perhaps the most studied. Different block copolymers with AB, ABA, and ABC architectures have been synthesized by controlled ROP. By the combination of ROP of PPE with other controlled polymerization methods, such as living radical polymerization, or click chemistry, more complex architectures including miktoarm, comb, or graft copolymers can be synthesized. The richness of structures has allowed the convenient adjustment of material properties of PPE for biomedical applications. 

A-P(MeOx)-AA MMA Living cationic DS in water and acetone -P(EtOx)-A polymerization, free DS in water, toluene, and acetone, DSC, DMTA radical Chemical reaction between hydrophobic hyperbranched polymers or dendrimers and hydrophilic linear chains 90... 

Hyperbranched polymers were prepared from 3-(l-chloroethyl)-ethyl benzene by cationic pol)mierization [77], and from 4-[2-(phenyl)-2-(l-2,2,6,6-tetramethylpiperidinyloxy)ethyloxy]methyl styrene [78] or / -(chloromethyl)-styrene [79] by free radical polymerization. In the cationic living polymerization, the benzylic chloride of 3-(l-chloroethyl)-ethyl benzene is activated with SnCl4 in the presence of Bu4NBr [80,81], followed by low-temperature living... 

Recent advances in free radical living polymerization have allowed more facile preparation of hyperbranched polymers (Scheme 18). Thus, a styrene containing an initiating groups for a living free radical pol)mierization,... 

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