Polybutadiene block copolymers

We use polystyrene-Z>-polybutadiene block copolymers as the starting material with preformed polymer architecture. These polymers are comparatively cheap and easily accessible.1 For the present problems a series of narrowly distributed polystyrene-6-polybutadiene block copolymers with rather different molecular weights were synthesized via anionic polymerization (Figure 10.4, Table 10.1). As a test for the modification of technological products, a commercial triblock copolymer was also used. 

Figure 10.4. Drawing of the polystyrene-b-polybutadiene block copolymers used for amphiphilic modification.

Table 10.1. Polystyrene- -Polybutadiene Block Copolymers Used as Starting Materials 1...

Therefore, at room temperature Fluoro-PSB-II a thermoplastic elastomer with a soft polymer phase (fluorinated block) and a hard phase (PS-block), similar to the parental polystyrene-6-polybutadiene block copolymer. Depending on the relative volume fraction of both components and the continuity of the phases, the resulting bulk material is rubbery or a high-impact solid. 

Styrolux is an example of a nanostructured polymer which is used in food packaging. It is a polystyrene-polybutadiene block copolymer where polymer chains are build up of alternating polystyrene and polybutadiene blocks. These blocks appear as dark lamellae in the TEM image due to the staining of the polybutadiene with OSO4. This structured nanoscale architecture of the pol5mier, which can be controlled during manufacture, allows the optimum combination of impact resistance and transparency. 

Block copolymers of butadiene and vinyl-2-naphtalene (BVN) have been synthetized and studied by the same techniques as polybutadiene-poly(a-methyl styrene) and polystyrene-polybutadiene block copolymers They exhibit the same structures, namely lamellar and cylindrical as SB and BMS block copolymers ... 

Figure 4. Gel permeation chromatograms of a polystyrene/ polybutadiene block copolymer (SBD-4) Before hydrogenation and fractionation (lower) and after (upper).

Figure 8. Gel permeatioii chromatograms of polyisoprene/ polybutadiene block copolymers (IBD-2) arm (top) and star.

Fig. 39. Small-angle X-ray scattering profiles of a polystyrene/polybutadiene block copolymer (molecular weight of the blocks M = 18600) at different temperatures T above the order/disorder transition temperature. The points indicate the measured intensity values while the solid lines are obtained by fitting a one-parametric theoretical model...

Metalated PIB obtained by one-pot dehydrochlorination-metalation of tert chlorine-ended PIB by potassium-t-amylate/nBuLi and tBuOK/nBuLi mixtures was used to initiate the anionic polymerization of butadiene resulting PIB-polybutadiene block copolymers. ... 

UTR Utracki, L.W., Simha, R., and Fetters, L.J., Solution properties of polystyrene-polybutadiene block copolymers, J. Polym. Sci. PartA-2,6, 2051,1968. 

Utracki, L. A., Simha, R Fetters L. J Solution properties of polystyrene-polybutadiene block copolymers. Journal of Polymer Science Part A-2, Polymer Physics, 6(12), pp. 2051-2066 (1968). 

Ren, Y., Lodge, T.P., Hillmyer, M.A. Effect of selective perfluoroalkylation on the segregation strength of polystyrene—1,2-polybutadiene block copolymers. Macromolecules 35, 3889 (2002)... 

No.9, 1997,p.2067-75 STUDY OF THE CONFORMATIONS OF POLY(EPSILON-CAPROLACTAM) AND POLY(EPSILON-CAPROLACTAM)-POLYBUTADIENE BLOCK COPOLYMERS BY FTIR SPECTROSCOPY WITH PHOTOACOUSTIC DETECTION AND BY MICRO-RAMAN CONFOCAL SPECTROSCOPY Schmidt P Fernandez M R Pastor J M Roda J Czech Republic,Academy of Sciences ... 

FTIR spectroscopy with photoacoustic detection and micro-Raman confocal spectroscopy were used to study the conformations of poIy(epsilon caprolactam) and poly(epsilon-caprolactam)-polybutadiene block copolymers. In the block copolymers prepared by anionic polymerisation, the fraction of the planar conformation of poly(epsilon-caprolactam) chains decreased with increasing polybutadiene content. In the surface layers formed by rapid saw cutting and in the islands formed by microtome cutting, the content of the planar conformation was lowered. This was substantially increased by water treatment, especially at elevated temperatures. 15 refs. 

An elastomer which upon heating turns into regularly behaving linear polymer. Polystyrene-polybutadiene block copolymers, polypropylene blends with ethylene-propylene-diene terpolymer provide examples. 

The application of polymer-supported catalysts has now been extended to the synthesis of complexes between transition metal derivatives and structurally ordered macromolecular ligands to give catalytic systems exhibiting high activity and stereoselectivity. Polystyrene and polymethacrylate resin and polystyrene-divinylbenzene-polystyrene-polybutadiene block copolymers, as well as vinyl-functionalized polysiloxanes grafted onto silica, are very suitable polymers for heterogenization of mostly Pt and Rh complexes. Moreover, polyamides exhibit much higher thermal stability than conventional polystyrene supports (114). 

PolymGrizabiG Block Copolymars. Unsaturated hydrocarbon polymers with a large number of polymerizable double bonds can be used to prepare fully cross-linked vesicle membranes. This has been demonstrated for polybutadiene block copolymers (23,168) and methacroyl-fimctionalized block copolymers (87) using free-radical polymerization, and for polycinnamoylethylmethacrylate block copolymers using a [2-1-2] photoaddition (68). Poly(ethylene oxide-6-3-(trimethoxysilyl)propyl methacrylate) vesicles could be efficiently cross-linked with triethylamine (79,80). PLA-PNIPAM block copolymer vesicles were cross-linked by chain extension of the PNIPAM block using hexamethylene diacrylate (77). 

Another widely used approach is the in situ polymerization of an intractable polymer such as polypyrrole onto a polymer matrix with some degree of processibil-ity. Bjorklund [30] reported the formation of polypyrrole on methylcellulose and studied the kinetics of the in situ polymerization. Likewise, Gregory et al. [31] reported that conductive fabrics can be prepared by the in situ polymerization of either pyrrole or aniline onto textile substrates. The fabrics obtained by this process maintain the mechanical properties of the substrate and have reasonable surface conductivities. In situ polymerization of acetylene within swollen matrices such as polyethylene, polybutadiene, block copolymers of styrene and diene, and ethylene-propylene-diene terpolymers have also been investigated [32,33]. For example, when a stretched polyacetylene-polybutadiene composite prepared by this approach was iodine-doped, it had a conductivity of around 575 S/cm and excellent environmental stability due to the encapsulation of the ICP [34]. Likewise, composites of polypyrrole and polythiophene prepared by in situ polymerization in matrices such as poly(vinyl chloride), poly(vinyl alcohol), poly(vinylidine chloride-( o-trifluoroethylene), and brominated poly(vi-nyl carbazole) have also been reported. The conductivity of these composites can reach up to 60 S/cm when they are doped with appropriate species [10]. 

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