Block copolymers of poly

Some other degradable (i.e., nonvinyl-type) polymers have been reported as components for amphiphilic block copolymers. For example, Hsiue reported the synthesis of a block copolymer of poly(2-ethyl oxazoline) and PLA by ROP. They reported the use of ABA-type triblock copolymers as pH-responsive polymer... 

The polymeric disulfide iniferter consisting of poly(DMS) 33 was also similarly prepared (Eq. 31) [ 143,151 ]. Block copolymers of poly(DMS) with MMA or St were synthesized with from two to eight blocks of both sequences per chain. 

G.G. Malliaras, J.K. Herrema, J. Wildeman, R.H. Wieringa, R.E. Gill, S.S. Lampoura, and G. Hadziioannou, Tuning of the photo- and electroluminescence in multi-block copolymers of poly[(silanylene)-thiophene]s via exciton confinement, Adv. Mater., 5 721-723, 1993. 

Figure 6.6 Reactive extrusion block copolymer of poly(ethylene terephthalate) and polycaprolactone...

We have shown that polymeric micelles constmcted of block copolymers of poly(ethylene oxide) (PEG) and poly(L-asparate) containing the anticancer dmg (adriamycin, ADR) selectively accumulate at solid tumor sites by a passive targeting mechanism. This is likely due to the hydrophilicity of the outer PEG chains and micellar size (<100 nm) that allow selective tissue interactions [17,18]. Polymeric micelle size ranges are tailored during polymer synthesis steps. Carefully selection of block polymer chemistry and block lengths can produce micelles that inhibit nonselective scavenging by the reticuloendothelial system (RES) and can be utilized as targetable dmg... 

Chung, J. E., Yokoyama, M., Yamato, M., Aoyagi, T., Sakurai Y., and Okano, T. Thermo-responsive drug delivery from polymeric micelles constructed using block copolymers of poly(A-isopropylacrylamide) and poly(butylmethacrylate), J. Contr. Rel, 1999, 62, 115-127. 

Figure 25. A-D Immunofluorescence staining of vmculrn in vascular smooth muscle cells on day 3 after seeding on polymeric surfaces (medium supplemented with 10% fetal bovine serum). A poly(DL-lactic acid), PDLLA B block copolymer of poly(DL-lactic acid) and poly (ethylene oxide) (PEO), PDLLA-6-PEO C, E PDLLA-6-PEO with 5% GRGDSG-PEO-6-PDLLA D, F PDLLA-6-PEO with 20% GRGDSG-PEO-6-PDLLA. E, F Immunoperoxidase staining of bromodeoxyuridine (arrows) incorporated into DNA newly synthesized in vascular smooth muscle cells cultured for 3 days in serum-free medium on PDLLA-Z)-PEO with 5% (E) or 20% (F) GRGDSG-PEO-6-PDLLA. Cells counterstained with light green. Bar=100 pm [41].

Based on this approach Schouten et al. [254] attached a silane-functionalized styrene derivative (4-trichlorosilylstyrene) on colloidal silica as well as on flat glass substrates and silicon wafers and added a five-fold excess BuLi to create the active surface sites for LASIP in toluene as the solvent. With THF as the reaction medium, the BuLi was found to react not only with the vinyl groups of the styrene derivative but also with the siloxane groups of the substrate. It was found that even under optimized reaction conditions, LASIP from silica and especially from flat surfaces could not be performed in a reproducible manner. Free silanol groups at the surface as well as the ever-present impurities adsorbed on silica, impaired the anionic polymerization. However, living anionic polymerization behavior was found and the polymer load increased linearly with the polymerization time. Polystyrene homopolymer brushes as well as block copolymers of poly(styrene-f)lock-MMA) and poly(styrene-block-isoprene) could be prepared. 

Topp MDC, Dijkstra PJ, Talsma H, Feijen J. Thermosensitive micelle-forming block copolymers of poly(ethylene glycol) and poly(iV-isopropylacrylamide). Macromolecules 1997 30 8518-8520. 

Ceresa synthetized also block copolymers of poly(methyl methacrylate) with acrylonitrile and styrene and of polyethylene with methyl methacrylate, styrene using this method (104). 

Dubief et al. (5) prepared cationic block copolymers of poly(styrene-co-iV-methyl-4-vinylpyridinium iodide), which were used in washing compositions. 

Abbreviations coiX-V] = copolymers of X and Y colX-b-Yl = block copolymers of poly X and poly Y ST = styrene MA = methyl acrylate MMA = methyl methacrylate AN = acrylonitrile BD = butadiene LR (liquid rubbers) = a, cj-polybutadiene-diols and -dicarboxylic acids Cell-Ac = cellulose acetate Cell-N02 = cellulose nitrate. 

The melting of a crystalline-amorphous block copolymer of poly(tetrahydro-furan)-poly(isoprene) (PTHF-PI) was investigated using DSC by Ishikawa et al. (1991). They found a double melting peak, which was proposed to result from the semicrystalline structure of the crystalline PTHF layer, with less-ordered crystallites melting before those with well-ordered domains of chain-folded PTHF. Alternative explanations include fractionation of the polydisperse block copolymer or melting of crystals with different fold lengths. 

Attempts have been made to deposit water-soluble poly(ferrocenylsilanes) on surfaces via layer-by-layer self assembly.17 Block copolymers of poly(ferrocenylsilanes) with poly (ethylene oxide) self-assemble in aqueous media to form redox active micelles.17... 

High-pressure static and dynamic light scattering were used to closely examine the behavior of block copolymers of poly(vinyl acetate) (PVAc) and poly(l,l,2,2-tetrahydroperfluoroalkyl acrylate (PTAN) as a function of C02 density (Buhler et al., 1998). The phase diagram for PVAc-6-TAN shows three distinct phases as a function of polymer concentration and C02 density at a fixed temperature of 45 °C (see Figure 9.1). The block copolymer forms a precipitated phase at low C02 densities, spherical micelles at intermediate C02 densities, and unimers, or free polymer chains in solution, at high densities. The micelles-to-unimer transition was found to be very... 

Kwon, G., Naito, M., Yokoyama, M., et al. Micelles based on AB block copolymers of poly(ethylene oxide) and poly(benzyl-aspartat). Langmuir 9 945—949. 1993. 

McCullough and coworkers had synthesized block copolymers of poly(3-hexylthiophene) and polystyrene or PMA by ATRP of the vinyl monomer from a polythiophene macroinitiator, which was prepared in several steps... 

Recently, Dai, Su, and coworkers synthesized the block copolymer of polythiophene and polypyridine from the vinyl-terminated polythiophene (Scheme 102) [336]. Meijer and coworkers used an allyl-terminated polythiophene to synthesize a block copolymer of poly(3-hexylthiophene) and polyethylene the ring-opening metathesis polymerization of cyclooctene in the presence of the allyl-terminated polythiophene was followed by hydrogenation (Scheme 103) [337]. 

The interfacial properties of an amphiphilic block copolymer have also attracted much attention for potential functions as polymer compatibilizers, adhesives, colloid stabilizers, and so on. However, only a few studies have dealt with the monolayers o well - defined amphiphilic block copolymers formed at the air - water interface. Ikada et al. [124] have studied monolayers of poly(vinyl alcohol)- polystyrene graft and block copolymers at the air - water interface. Bringuier et al. [125] have studied a block copolymer of poly (methyl methacrylate) and poly (vinyl-4-pyridinium bromide) in order to demonstrate the charge effect on the surface monolayer- forming properties. Niwa et al. [126] and Yoshikawa et al. [127] have reported that the poly (styrene-co-oxyethylene) diblock copolymer forms a monolayer at the air - water... 

Fig. 2 Response of various PECs (first polyelectrolytes in initial solutions) to subsequent addition of salt a particle mass Mw b particle radius am (corrected for polydispersity, obeying the relation Mw=(4/r/3) p am3), c structure density p 1( ) - NaPSS/PDADMAC, X=0.3, 2(0) - NaPSS/PDADMAC, X=0.6, 3(B) - DADMAC-acrylamide copolymer (47 mol% DADMAC)/NaPMA X=0.6, 4(V) - DHP2 (block copolymer of poly(2-acry-lamido-2-methyl-1-propanesulfonic acid) and poly(ethylene glycol), PEG block length 10 kda)/PDADMAC, X=0.6,1-4 addition of NaCl, 5(A) - DADMAC-acrylamide copolymer (47 mol% DADMAC)/Na-PMA, X=0.6, addition of CaCl2...

A block copolymer 55 consisting of a polystyrene block and a poly (CL) block was found to be an effective blending agent for the combination between polystyrene and poly(vinyl chloride). A po ybutadiene/poly(CL) block copolymer was an efficient blending agent for a mixture of polybutadiene and polyacrylonitrile. In addition, a block copolymer of poly(hydrogenated 1,4-butadiene) with poly(CL) allows a three-component mixture of polystyrene, polyethylene and poly(vinyl chloride) to be blended. 

Poly (iso butylene) glycol is a suitable rubbery segment in thermoplastic elastomers. An oligomer such as 56 with a tertiary chloro group at both ends could be employed also as the initiator of cationic polymerization of a-methylstyrene (a-MeSt) in the synthesis of a three-block copolymer of poly(a MeSt)-polyisobutylene-poly(a-MeSt)52). 

The intramacromolecular complexation of the block copolymer of poly(sty-renesulfonic acid) (PSS)-poly(2-vinylpyridine) (P2VP) has recently been reported. Varoqui et al.435) have synthesized this block copolymer and investigated its solution properties. They observed a great increase in the basicity of the pyridyl groups in the block copolymer. This phenomenon was explained by invoking a stoichiometric interaction between oppositely charged blocks. 

Neradovic, D.,Soga, O., Van Nostrum, C. F., and Hennink,W. E. (2004),The effect of the processing and formulation parameters on the size of nanoparticles based on block copolymers of poly(ethylene glycol) and poly(AMsopropylacrylamide) with and without hydrolytically sensitive groups, Biomaterials, 25(12), 2409-2418. 

Sanderson [2] prepared the energetic thermoplastic elastomer poly(3,3-bis (azidomethyl)-oxetane), (II), for use as a binder for a propellant, explosive, or gas generant for a supplemental restraint system in automobiles. Random block copolymers of poly(azidomethyloxirane) and poly(3,3-bis(azidomethyl)oxe-tane), (III), were also prepared by Sanderson [3] using toluene diisocyanate as the coupling agent. 

The thickness of horizontal filns of n-decane sandwiched between two water (or aqueous electrolyte) droplets has been determined by a light reflectance technique. The films were stabilised by three surfactants an xyx block copolymer of poly(ethyleneoxide) and poly(12-hydroxystearic) acid soya bean lecithin Arlacel 83 (sorbitan sesquioleate). Results obtained for two and three component mixtures of the surfactants were compared with those for the single surfactants. The results showed that, provided sufficient polymer is present in the film, the thickness is determined by the longest oleophilic chain, namely the poly(12-hydroxystearic) acid. 

C. Block-Copolymers of Poly tyrene-Poly(dimethylsiloxane) (88)... 

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