Block copolymers containing

Step-Growth Gopolymerization. A sample of a block copolymer prepared by condensation polymerisation is shown in equation 30 (37). In this process, a prepolymer diol (HO—Z—OH) is capped with isocyanate end groups and chain extended with a low molecular-weight diol (HO—E—OH) to give a so-called segmented block copolymer, containing polyurethane hard blocks and O—Z—O soft blocks. 

Closely related to these but thermoplastic rather than rubber-like in character are the K-resins developed hy Phillips. These resins comprise star-shaped butadiene-styrene block copolymers containing about 75% styrene and, like SBS thermoplastic elastomers, are produced by sequential anionic polymerisation (see Chapter 2). 

Polyaddition reactions based on isocyanate-terminated poly(ethylene glycol)s and subsequent block copolymerization with styrene monomer were utilized for the impregnation of wood [54]. Hazer [55] prepared block copolymers containing poly(ethylene adipate) and po-ly(peroxy carbamate) by an addition of the respective isocyanate-terminated prepolymers to polyazoesters. By both bulk and solution polymerization and subsequent thermal polymerization in the presence of a vinyl monomer, multiblock copolymers could be formed. 

Block copolymers containing polysiloxane segments are of great interest as polymeric surfactants and elastomers. Polycondensation and polyaddition reactions of functionally ended prepolymers are usually employed to prepare well-defined block copolymers. The living polystyrene anion reacts with a,co-dichloropoly(dimethyl-siloxane) to form multiblock copolymers398. ... 

Hamley IW, Ansari A, Castelletto V et al (2005) Solution self-assembly of hybrid block copolymers containing poly(ethylene glycol) and amphiphilic beta-strand peptide sequences. 

Liu B, Lewis AK, Shen W (2009) Physical hydrogels photo-cross-linked from self- assembled macromers for potential use in tissue engineering. Biomacromolecules 10 3182-3187 Vandermeulen GWM, Tziatzios C, Duncan R et al (2005) Peg-based hybrid block copolymers containing alpha-helical coiled coil peptide sequences control of self- assembly and preliminary biological evaluation. Macromolecules 38 761-769... 

Synthesis and Characterization of Block Copolymers Containing Acid and Ionomeric Functionalities... 

AB Block Copolymers Containing Methacrylic Acid and/or Metal Methacrylate Blocks... 

Significant modification in properties of polymers and block copolymers containing isoprene and/or butadiene have been reported following hydrogenation of these macromolecules.(9,13-18)... 

As already mentioned, the HB block is semicrystalline and its general behavior is similar to that of LDPE. The HI block on the other hand is amorphous and rubbery at ambient temperature. The material behavior of block copolymers containing HB and HI blocks will now be discussed in the following sections. 

Polysaccharides are hydrophilic natural polymers that can be degraded enzymatically. Block copolymers containing polysaccharide as a block were reviewed recently... 

A similar technique was applied to the synthesis of AB and ABA block copolymers containing random and alternating copolymer sequences [178-180]. For example poly(St-ra dora-MMA)-hZock-poly(VAc), poly(VAc-hZock-poly(St-ran-dora-MMA)-hZock-poly(VAc), poly(St)-foZoc/c-poly(DiPF-aZMBVE), poly(IBVE-aZf-MAn)-hZock-poly(St)-hZock-poly(IBVE-aZf-MAn), poly(St)-hZock-poly(EA)-random-AA), and poly(St)-hZock-poly(EA-ra dora-AA-random-MMA) were synthesized [178]. 

A totally different route based on dehydrogenation of a saturated polymer precursor was introduced by Francois et al. [49] (Scheme 2.9). The method is based on anionic copolymerization of cyclohexadiene with styrene, followed by oxidation with chloranil. Due to possible coupling of two styrene (or two cyclohexadiene) molecules, a block copolymer, containing oligo(phenylene vinylene) units separated by oligo(phenylacetylene) and oligo(phenylene) blocks, is obtained. To the best of our knowledge, it was, so far, used only in the synthesis of phenyl-substituted PPV 10. 

X. Kong and S.A. Jenekhe, Block copolymers containing conjugated polymer and polypeptide sequences synthesis and self-assembly of electroactive and photoactive nanostructures, Macromolecules, 37 8180-8183, 2004. 

Block copolymer micelles with a polyelectrolyte corona are a very important class of colloidal particles in aqueous medium and are often referred to as polyelectrolyte block copolymer micelles. The micellization behavior of these charged micelles has been very recently reviewed by Riess [14] and FOrster et al. [15]. A brief overview of the topic will therefore be presented in what follows. Amphiphilic block copolymers consisting of one hydrophobic block linked to one ionic block will only be discussed in this section. Blocks copolymers containing one hydrophilic block and one ionic block will be discussed in Sect. 4.3. 

AB block copolymers containing two water-soluble blocks are often referred to as double-hydrophilic block copolymers. These copolymers have spurred much interest in recent years because they can generally be transformed into amphiphilic copolymers once an adequate stimulus is applied. In other words, one of the hydrophilic water-soluble blocks can be transformed into a hydrophobic block whenever a given property of the aqueous medium is changed. Since these copolymers may contain one or two polyelectrolytic blocks, the typical features of polyelectrolytes described in Sect. 4.2 should also be considered for some double-hydrophilic block copolymers. 

Fig. 20 Cryo-TEM image of isolated micelles and segmented rods made from miktoarm ABC block copolymers containing PEO, PB and perfluorinated polyether blocks (scale bar is 50 nm). A schematic representation of the stacking of block copolymer chains in segmented worms is also shown. Reprinted with permission from [284], Copyright (2004) American Association for the Advancement of Science...

In a very recent set of papers [48,54,59,60,131,132,324-328], the synthesis and characterization of metallosupramolecular amphiphilic block copolymers containing a hydrophilic PEO block linked to a hydrophobic PS or PEB block through a fozs-2,2/ 6/,2/terpyridine-ruthenium(II) complex have been described. These copolymers form the so-called metallosupramolecular micelles . 

As described in Sect. 7.1, novel hybrid block copolymers comprising on one hand a classical synthetic polymer and on the other hand a metal-containing polymer, a synthetic or natural (proteine, enzyme, etc.) polypeptide have recently been synthesized. Other hybrid block copolymers containing inorganic blocks, dendrimers, etc. will certainly be prepared and thoroughly investigated in the next few years. 

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