PS b poly

Fig. 8. Thermogravimetric analysis of polymers and copolymers of styrene in nitrogen at 10°C/min A represents PS B, poly(vinyltoluene) C, poly(a-methylstyrene) D, poly(styrene-i (9-acrylonitrile), with 71.5% styrene E, poly(styrene-i (9-butadiene), with 80% styrene and F,...

Block copolymers with PS and a polymethacrylate block carrying a liquid crystalline group, PS-b-poly 6-[4-(cyanophenylazo)phenoxy]hexyl methacrylate, were successfully prepared in quantitative yields and with relatively narrow molecular weight distributions (Scheme 5) [18]. The thermotropic liquid crystalline behavior of the copolymers was studied by differential scanning calorimetry. 

Ishizu et al.194 synthesized hyperbranched macromolecules that resemble dendrimers. The synthetic approach involved the preparation of poly(4-methyl-styrene-b-PS-b-poly(4-methylstyrene) triblock copolymer by using naphthalene lithium as difunctional initiator. The 4-methyl groups of the terminal blocks were metalated with s-BuLi/tetramethylethylenedi-amine (TMEDA) complex in a molar ratio of 1 2. After removal of the excess s-BuLi by repeated precipitation of the living polymer and transfer of supernatant solution to another flask under high vacuum conditions, the polymer was dissolved in THF and was used as the initiator of a-methylstyrene at —78 °C. After the polymerization of a-methylstyrene, a small amount of 4-methylstyrene was added. The procedure of metalation of the a-methyl groups and polymerization of a-methylstyrene can be repeated many times to form a dendritic type hyperbranched polymer (Scheme 99). The characterization of the inter-... 

Phenyl vinyl sulfoxide (8) shows a high anionic polymerizability, similar to that of (meth)acrylates and N,N-dialkylacrylamides [158-160]. Hogen-Esch first reported that 8 underwent anionic polymerization in TH F at — 78 °C to afford polymers with relatively narrow molecular weight distributions (Mw/M = 1.1-1.5) [158]. AnAB diblock copolymer, PS-b-poly(8), was also synthesized by the sequential addition of styrene, followed by 8. Subsequently, the anionic polymerization was improved by using 4-methylphenyl vinyl sulfoxide (9) with l,l-diphenyl-3-methylpentyllithium in the presence of a 20-fold excess of liCl in THF at —78°C [161]. In this way. 

FIGURE 8.1 Chemical structure of (a) polystyrene (PS), (b) poly(methyl methacrylate) (PMMA), (c) 8-hydroxyqui-noline (8HQ), (d) 1-dodecanethiol (DT), (e) 2-naphthalenethiol (2NT), (f) polyaniline (PANI), (g) tetrathiafiilvalene (TTF), and (h) methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM). 

The OH group was protected by reaction with tert-butyldimethylsilyl chloride (TBDMS) in order to obtain the living anionic polymerisation. Diphenylethylene (DPE) was used to lower the living chain reactivity. The monomers were added in order styrene, styrene-o-TBDMS, DPE, MMA to the solvent tetrahydrofuran (THF) at 78°C in nitrogen with stirring. The reaction was terminated with methanol and precipitated by hexane to give the product PS-b-poly(styrene-o-TBDMS)-b-PMMA which was dried in vacuum at 130°C then... 

PS-polydimethylsiloxane (PS-PDMS), polyimides containing thermally labile blocks such as poly(methyl methacrylate) (PMMA) or poly(propylene oxide) (PPO), poly(f-butylacrylate)-b-poly(2-cinnamoylethyl methacrylate) (PtBAPCEMA), poly-styrene-b-poly(methyl methacrylate) (PS-b-PMMA), PS-poly(perfluorooctylethyl methacrylate) (PS-PFMA), PS-polylactide (PS-PLA), and PS-b-poly-4-vinylpyridine (PS-PVP). 

PS 10200 M IM = 1.07) and a poly(ethyl ethylene) with = 4080 (PBDH 4080 M IM = 1.04), which was prepared by hydrogenation of poly(vinyl ethylene), PVE. The interaction parameter values used, x = 0.0057 + 21/T, were evaluated by analyzing small-angle X-ray scattering data from homogeneous PS-b-poly(ethyl ethylene) diblock copolymers [245] the blend exhibits a UCST behavior. 

Favis and coworkers [51, 52] critically examined the relationship between the interfacial tension reduction in the presence of diblock copolymer additives and the dispersed phase morphology evolution as a function of the concentration of the interfacial modifier. Blends of PS/PE in the presence of PS-b-hydrogenated poly-butadiene-b-PS (Kraton, SEBS) [51] and of PE/PVC in the presence of Pl-l>-poly (4-vinyl pyridine) or PS-b-poly(acrylic acid) [52] were investigated. The authors unambiguously confirmed directly the relationship between interfacial tension and phase size, as predicted by the Taylor theory [280]. 

The expression for the interaction parameter xsans in Eq. 43 is specialized below for PS-b-poly( -alkyl methacrylate) diblock copolymer melts. The monomer structures for both the styrene (sa = is = 8) and -alkyl methacrylate (sb = S/i-AMA = 6 + n) monomers are depicted in Fig. 14. Stiffness in the styrene molecule is introduced into our model by treating the two pairs of styrene side group bonds (Fig. 14) as completely rigid (n2%iff )- hi order to minimize the munber of adjustable parameters, we distinguish only three types of united atom imits in aU these diblock copolymer systems considered alkyl CH groups (n = 0, 1, 2, or 3), aromatic CH groups... 

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