Hybrid copolymer

The same research group recently carried out the synthesis of other hybrid copolymers in which hydrophobic PS chains had been covalently linked to natural polypeptides such as a lipase enzyme [264], The resulting biohybrid has been referred to as a giant amphiphile and forms catalytic micellar rods in water, as shown in Fig. 17. 

Regardless of the desired architecture, there are three main synthetic approaches to the preparation of diblock, dumbbell or dendronized hybrid copolymers. These involve grafting, polymerization or stepwise dendritic growth... 

Figure 7.5 Hybrid copolymers with functionalized dendrons and their assembly on a surface...

In one of several important studies on dendronized polymers [4c, 4d]. Schluter and coworkers explored the stiffening of polystyrene chains through the incorporation of Frechet-type dendrons as side chains [28, 29]. While the G-l and G-2 dendrons were not sufficiently bulky to effectively stiffen the polystyrene chain, the G-3 dendron provides enough steric bulk to force the hybrid polymer into adopting a cylindrical shape in solution [28b], In a complementary study, Neubert and Schluter demonstrated that adding charges to the dendritic wedges leads to an expansion of the chains of the hybrid copolymer in aqueous solution [29],... 

As this brief overview demonstrates, novel copolymers obtained by hybridization of the linear and globular architectural states are readily prepared through a variety of synthetic approaches. In general the dendritic components of the hybrid copolymers are well defined, with unique molecular and structural characteristics. In contrast, all the linear components prepared polymerization are less precisely defined and are polydisperse. Only the very short linear components, themselves prepared by stepwise synthesis just like the dendrons, are monodisperse and can be used to prepare well-defined, monodisperse hybrids. While architectural and structural precision may be of great importance for the determination of ultimate properties, some degree of structural variation is quite acceptable for practical applications in many areas including, for example, surface modification, sensing, or encapsulated delivery. 

Metzke M, O Connor N, Maiti S et al (2005) Saccharide-peptide hybrid copolymers as biomaterials. Angew Chem Int Ed 44 6529-6533... 

Deming T. ]. Polypeptide and Polypeptide Hybrid Copolymer Synthesis viaNCA Polymerization. Vol. 202, pp. 1-18. 

The rationale for preparing this hybrid copolymer was to combine the desirable properties of polyaniline with those of polythiophene. For example, polythiophene has demonstrated thermo- and electrochromism, solvatochromism, luminescence, and photoconductivity while polyaniline has demonstrated reversible protonic dupability, excellent redox re-cyclability, and chemical stability. 

Haeupke et al. found that gel and half-porous copolymers may become porous after being modified with a second monomeric phase containing an inert diluent. Such modified copolymers are called double porous copolymers (Haeupke et al. ) or hybrid copolymers (Barrett and Clemens ). 

A hybrid copolymer has been prepared by the modification of SDVB macro-reticular copolymer with methyl acrylate and DVB. Under the conditions of intermesh copolymerization, about 14% of methyl acrylate-DVB copolymer could be intro-... 

Because of their exceptional behavior and process ability, silicone-based copolymers will take then-place as specialties within the silicone polymer class. With these silicone hybrid copolymers, new possibilities open up for adding value and performance to polymer and additive formulations. 

Silicone Hybrid Copolymers — Structure, Properties, and Characterization... 

Silicone Hybrid Copolymers - Structure, Properties, Characterization 803... 

Polypeptide and Polypeptide Hybrid Copolymer Synthesis via NCA Polymerization... 

Abstract This article summarizes recent developments in the synthesis of polypeptides and hybrid peptide copolymers. Traditional methods used to polymerize -amino acid-N-carboxyanhydrides (NCAs) are described, and limitations in the utility of these systems for the preparation of polypeptides are discussed. Recently developed initiators and methods are also discussed that allow polypeptide synthesis with good control over chain length, chain length distribution, and chain-end functionality. The latter feature is particularly useful for the preparation of polypeptide hybrid copolymers. The methods and strategies for the preparation of such hybrid copolymers are described, as well as analysis of the synthetic scope of the different methods. Finally, issues relating to obtaining these highly functional copolymers in pure form are detailed. 

Keywords Polypeptide Block copolymer N-carboxyanhydride Living polymerization Hybrid copolymer... 

Synthetic peptide-based polymers are not new materials homopolymers of polypeptides have been available for many decades and have only seen hmited use as structural materials [5,6]. However, new methods in chemical synthesis have made possible the preparation of increasingly complex polypeptide sequences of controlled molecular weight that display properties far superior to ill-defined homopolypeptides [7]. Furthermore, hybrid copolymers, that combine polypeptide and conventional synthetic polymers, have been prepared and combine the functionality and structure of peptides with the processabihty and economy of polymers [8,9]. These polymers are well suited for applications where polymer assembly and functional domains need to be at length scales ranging from nanometers to microns. These block copolymers are homogeneous on a macroscopic scale, but dissimilarity between the block segments typically results in microphase heterogeneity yield-... 

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