Comb copolymers, block copolymer-based

To obtain improved ionic mobility, and thus high conductivity, alternative polymer structures have been developed, for example comb-branched block copolymers such as poly[bis(methoxy ethoxy ethoxide)], usually known as MEEP. Room temperature conductivities of MEEP-based polymer electrolytes of the order of 10-5 S/cm have been achieved, values... 

Block Copolymer-Based Hydrogen-Bonded Comb Copolymers. 137... 

Finally, we will consider briefly the formation of multilayer thin films by layer-by-layer deposition of hydrogen-bonded polymer pairs [51,52]. In this way a multilayer structure is obtained from potentially miscible polymer pairs. The stability of these films very much depends on the presence of hydrogen bonds, and pH may be used as an external trigger to erase the layered structure [53,54] and selectively dissolve one of the components [25-27]. This procedure allows for the preparation of microporous films not unlike the nanoporous films obtained by dissolution of the hydrogen-bonded side groups from self-assembled block copolymer-based comb-shaped supramo-lecules [15,17,18]. 

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. 

These inerts are mostly polymeric or oligomeric in nature and can be both nonionic and anionic. They have multiple binding / interaction sites to the interface, so that a displacement becomes improbable. Several materials have been made available to the industry [6d,ej. The chemistries range from sulfonic condensates (Morwet) or lignin sul-phonates (Reaxx) to EO-PO-block copolymers (Pluronics), comb graft polymers, acrylate based copolymers or various other block copolymers. 

Compared to block copolymers, there have been relatively fewer examples of using homopolymers for nanofabrication. Nevertheless, some polymers with amphiphilic properties were also used in the fabrication of nanostructures with various metal salts/complexes. For example, polyaniline (PANI) emeraldine base formed self-organized mesomorphic structures when mixed with Zn(DBS)2 by the coordination between Zn2+ and the imine nitrogen atoms on the polymer main chain.100 The resulting supramolecule PANI[Zn(DBS)2]0.5 had a comb-shaped... 

As for any block copolymer, the self-organized structure formation in comb copolymers is based on the competition between the covalent attraction and the repulsion between the side chains and the backbone. The examples employing ionic attraction and coordination complexation demonstrate that the attractive interaction has to be sufficiently strong. In the case of hydrogen bonding, this is a much more delicate matter and the strength required to self-organize the supramolecular comb copolymers will be determined by a fine balance between attraction and repulsion. 

A grafted copolymer (Heveaplus MG) based on natural rubber has been available for many years. In distinction to the synthetic block copolymers which have been introduced into adhesive technology, Heveaplus MG is a comb-type material having a natural rubber backbone and poly methyl methacrylate side chains. 

Reversible addition-fragmentation chain transfer polymerization (RAFT) polymerization of methyl acrylate was combined with cationic polymerization of THF to synthesize comb copolymers. Asymmetric star block copolymers based on polystyrene (PS), PTHF, and PMMA were synthesized by a combination of CROP and redox polymerization methods. Miktoarm star polymers containing poly(THF) and polystyrene arms were also obtained by combining CROP and ATRP methods. Another approach for the synthesis of block copolymers... 

Comb-branched copolymer and block copolymer architectures are similar in that they are generally based on short polyether chains supported in some manner to give the material its mechanical stability. Success has been variable in attempts to... 

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