Styrene-cO-divinylbenzene

FIG. 20-92 SEM image of a poly(styrene-co-divinylbenzene) gigaporous particle synthesized from suspension polymerization and schematic of a gigaporous particle showing through-pores and diffusion pores [Gu et al., China Partic-uology, 3, 349 (2005)]. 

Virklund, C., Nordstrom, A., Irgum, K. (2001). Preparation of porous poly(styrene-co-divinylbenzene) Monoliths with controlled pore size distributions initiated by stable free radicals and their pore surface functionalization by grafting. Macromolecules 34, 4361-... 

Polystyrene-co-butylacrylate, 7 608t Poly (styrene-co-divinylbenzene), 73 113 Poly(styrene-co-vinylpyridinium methyl iodide) ionomer system, 74 480 Poly(styrenedivinylbenzene) (PSDVB) liquid chromatography stationary phase, 4 623... 

Zhang developed a monolithic poly(styrene-co-divinylbenzene) CEC column in which the EOF is supported by carboxyl groups of polymerized methacrylic acid [ 133]. Using benzene as a probe, column efficiencies of 90,000 -150,000 were observed within a flow velocity range of l-10cm/min (0.2-1.7 mm/s). Different families of compounds such as phenols, anilines, chlorobenzenes, phenylendi-amines, and alkylbenzenes were well separated typically in less than 5 min using 20 cm long columns. 

Recent chromatographic data indicate that the interactions between the hydrophobic surface of a molded poly(styrene-co-divinylbenzene) monolith and solutes such as alkylbenzenes do not differ from those observed with beads under similar chromatographic conditions [67]. The average retention increase, which reflects the contribution of one methylene group to the overall retention of a particular solute, has a value of 1.42. This value is close to that published in the literature for typical polystyrene-based beads [115]. However, the efficiency of the monolithic polymer column is only about 13,000 plates/m for the isocratic separation of three alkylbenzenes. This value is much lower than the efficiencies of typical columns packed with small beads. 

Fig. 12. Separation of styrene oligomers by reversed-phase (left) and size-exclusion chromatography (right) (Reprinted with permission from [121]. Copyright 1996 American Chemical Society). Conditions (left) column, molded poly(styrene-co-divinylbenzene) monolith, 50 mm x 8 mm i.d., mobile phase, linear gradient from 60 to 30% water in tetrahydrofuran within 20 min, flow rate 1 ml/min, injection volume 20 pi UV detection, 254 nm (right) series of four 300 mm x 7.5 mm i.d. PL Gel columns (100 A, 500 A, 105 A, and Mixed C), mobile phase tetrahydrofuran, flow rate, 1 ml/min injection volume 100 pi, toluene added as a flow marker, UV detection, 254 nm temperature 25 °C,peak numbers correspond to the number of styrene units in the oligomers...

Fig. 16. Separation of cytochrome c (1), myoglobin (2), and chicken egg albumin (3) by re-versed-phase chromatography on a monolithic poly(styrene-co-divinylbenzene) column at flow rates of a 5 ml/min b 25 ml/min. (Reprinted with permission from [53]. Copyright 1996 American Chemical Society). Conditions column 50 mmx8 mm i.d., mobile phase linear gradient from 20 to 60% acetonitrile in water... 

Huber s group recently prepared poly(styrene-co-divinylbenzene) monolithic columns in the capillary format using tetrahydrofuran/decanol mixtures as poro-gen. These columns were tested for the HPLC separation of protein digests followed by ESI MS detection enabling protein identification [129]. This technique represents an important contribution to the currently emerging techniques for studying of proteomes as it is more convenient and accurate to use than the classical 2-D gel electrophoresis. 

Fig. 17. Rapid reversed-phase separation of proteins at a flow-rate of 10 ml/min (Reprinted with permission from [127]. Copyright 1999 Elsevier). Conditions Column, 50x4.6 mm i.d. poly(styrene-co-divinylbenzene) monolith,mobile phase gradient 42% to 90% acetonitrile in water with 0.15% trifluoroacetic acid in 0.35 min, UV detection at 280 nm. Peaks ribonucle-ase (1), cytochrome c (2), bovine serum albumin (3), carbonic anhydrase (4), chicken egg albumin (5)...

Fig. 18a-c. Base peak chromatograms for the LC/MS analyses of a cytochrome c Lys-C digest (0.7 pmol injected) on a a poly(styrene-co-divinylbenzene) monolith-filled needle b Vydac C18-packed needle c Poros R2-packed needle. (Reprinted with permission from [128]. Copyright 1998 American Chemical Society)... 

A mechanistic study by Haynes et al. demonstrated that the same basic reaction cycle operates for rhodium-catalysed methanol carbonylation in both homogeneous and supported systems [59]. The catalytically active complex [Rh(CO)2l2] was supported on an ion exchange resin based on poly(4-vinylpyridine-co-styrene-co-divinylbenzene) in which the pendant pyridyl groups had been quaternised by reaction with Mel. Heterogenisation of the Rh(I) complex was achieved by reaction of the quaternised polymer with the dimer, [Rh(CO)2l]2 (Scheme 11). Infrared spectroscopy revealed i (CO) bands for the supported [Rh(CO)2l2] anions at frequencies very similar to those observed in solution spectra. The structure of the supported complex was confirmed by EXAFS measurements, which revealed a square planar geometry comparable to that found in solution and the solid state. The first X-ray crystal structures of salts of [Rh(CO)2l2]" were also reported in this study. 

Zhang s group in China developed monolithic poly(styrene-co-divinylbenzene) CEC column in which EOF is supported by carboxyl groups of polymerized methacrylic acid units (Xiong etal. [51]). In a typical procedure, vinylized 75 mm i.d. capillaries were filled with a mixture of 5% styrene 21, 10% divinylbenzene 22, 5% methacrylic acid 1, and 80% toluene containing 1% azobisisobutyronitrile (in respect to monomers) and polymerized at 70°C for 24 h. The pore volume of 0.098 mL/g and mean pore size of 40 nm determined for this monolith appear to be rather small and do not correspond with the published SEM pictures that reveal existence of large pores, and the chromatographic performance of the columns in CEC mode. 

Poly(4-vinylpyridine-co-styrene-co- divinylbenzene) were supplied in the form of beads (Reillex 425 and Purolite ) or prepared as thin films (dimensions ca. 76 x 14 mm x 40-120 pm) at the University of Strathclyde.11 Quatemisation of the pyridine groups was carried out by slow addition of the polymer (typically 1 g) to ethanol (40 cm3) To this was added methyl iodide (2 cm3) and the mixture was heated to 50 °C for 2 hours and then cooled. The quatemised polymer was washed with ethanol followed by acetone and then vacuum dried. 

A logical way of increasing the fraction of transition metal atoms used for active centre formation seems to be the application of the metal compound to a polymer surface [189], The carrier could be identical with, or similar to, the product. This approach is being intensively studied, and various polymers are being tested as carriers, for example poly(styrene-co-divinylbenzene) [190], chloromethylated poly(styrene-co-divinylbenzene) [191], poly-ethylene-0ra/t-poly(4-vinylpyridine) [192], and many others. 

In another approach, reactive monodisperse porous poly(chloromethylstyrene-co-styrene-co-divinylbenzene) beads have been employed for the preparation of chiral HPLC packings. Thus, reactive chloromethyl groups were derivatized to yield amino functionalized beads onto which both rt-basic and rt-acidic type chiral. selectors, (/ )- -(l-naphthyl)ethylamine and (/ )-A -(3.5-dinitrobenzoyl)phenylglycine, respectively, were attached. The resulting chiral particles were chromatographically tested for the enantioseparation of model SAs. Despite the presence of strongly competitive it-TT-binding sites of the styrenic support these chirally modified beads afforded baseline separations for 2,2,2-trifluoro-l-(9-anthryl) ethanol and Af-(3.5-dinitro-benzoyl) leucine enantiomers, respectively [369. ... 

Petro M, Svec F, Gitsov I, and Frechet JMJ. Molded monolithic rod of macroporous poly(styrene-co-divinylbenzene) as a separation medium for HPLC of synthetic polymers. Anal. Chem. 1996 68 315-321. 

Luo Q, Wei Y, Liu T, Lei G, and Geng X. Poly(chloromethyl) styrene-co-divinylbenzene continuous rod column of weak cation exchange chromatography and its applications in the separation of biopolymers. Chin. Chem. Lett. 1999 10 215-218. 

Xie SF, Allington RW, Svec F, and Frechet JMJ. Rapid reversed-phase separation of proteins and peptides using optimized moulded monolithic poly(styrene-co-divinylbenzene) columns. J. Chromatogr. A 1999 865 169-174. 

Figure 6.2.4. Result for a Py-GC/MS analysis ofpoly(styrene-co-divinylbenzene) 2% crosslinked. Pyrolysis done at 60(f C in He, with the separation on a Carbowax type...

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