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  • 1
    Electronic Resource
    Electronic Resource
    Monodisperse polymer beads as packing material for high-performance liquid chromatography. Synthesis and properties of monidisperse polystyrene and poly(methacrylate) latex seeds (1992)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 195 (1992), S. 151-164 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß von Initiatorkonzentration, Ionenstärke des Polymerisationsmediums, Polymerisationstemperatur und Monomer/Wasser-Phasenverhältnis auf Teilchengröße, Teilchengrößenverteilung und Molekulargewicht der gebildeten Polymeren bei der emulgatorfreien Emulsionspolymerisation von Styrol, Methylmethacrylat und Glycidylmethacrylat wurde untersucht. Für die Herstellung von Polystyrolpartikeln einheitlicher Größe (〉 1 μm) wurden die optimalen Bedingungen gefunden; für die anderen beiden Monomeren gelang dies nicht. Es wird gezeigt, daß die Quellfähigkeit “nichtaktivierter” Latexpartikel eine Volumenzunahme auf das 70fache nicht übersteigt und stark von der Größe der ursprünglichen Partikel abhängt.
    Notes: The effects of initiator concentration, ionic strength of polymerization medium, polymerization temperature, and monomer/water phase ratio on particle size, particle size distribution and molecular weight of the resulting polymers prepared by an emulsifier-free emulsion polymerization of styrene, methyl methacrylate and glycidyl methacrylate have been studied. Optimal conditions for preparation of uniformly sized polystyrene particles larger than 1 μm have been found. An attempt to synthesize monodisperse particles of similar size from methacrylate monomers and crosslinked particles has failed. It is shown that the swelling ability of “non-activated” latex particles does not exceed 70 fold increase in the volume and strongly depends on the size of the original particles.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1992.051950112
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  • 2
    Electronic Resource
    Electronic Resource
    Aminolysis of low-molecular-weight and polymeric 4-nitrophenyl esters (1988)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 189 (1988), S. 671-682 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 4-Nitrophenyl methacrylate (1a), 4-nitrophenyl esters of some N-methacryloyl-ω-amino acids (1b -d) and 4-nitrophenyl esters of N-acetyl- and N-methacryloyltryptophane (2a and 2b) were prepared and characterized. Copolymers of 1 a -d and 2 b with N-2-hydroxypropylmethacrylamide (HPMA), N-isopropylmethacrylamide (iPMA) and N-ethylmethacrylamide (EMA) were also prepared. The 4-nitrophenyl ester content of the copolymers was determined spectrophotometrically from their UV absorption and from the UV absorption of the 4-nitrophenolate ion which is released upon hydrolysis of the active esters with 0,1 M sodium hydroxide. The difference between these values depends on both the type of polymerizable active ester used and the comonomer. The proportion of non-hydrolyzable structure is especially high in the case of copolymers containing 4-nitrophenyl esters of the methacryloylated α-amino acids 1b and 2b. The formation of non-hydrolyzable structures is likely due to side reactions which occur during polymerization. The polymers prepared by copolymerization of the polymerizable 4-nitrophenyl esters were not found to be suitable for the preparation of polymeric fluorescent probes by a chemical modification route. It was found that the rate of aminolysis of low-molecular-weight and polymeric activated esters increases with increasing the number of methylene groups in the N-(ω-aminoalkyl)-5-dimethylamino-1- naphthalenesulfonamides (dansylamines) 3a-f.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1988.021890319
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  • 3
    Electronic Resource
    Electronic Resource
    Photogenerated base in polymer curing and imaging: Design of reactive styrenic copolymers susceptible to a base-catalyzed β-elimination (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 3543-3552 
    Details
    ISSN: 0887-624X
    Keywords: resist ; imaging ; photogenerated base ; elimination ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A novel family of functionalized styrenic copolymers that are susceptible to a base-catalyzed β-elimination reaction is reported. The reactive copolymers, poly-{(2-phenyl-2-cyanoethoxycarbonyloxystyrene)-co-(4-hydroxystyrene)}, are prepared by chemical modification of poly(4-hydroxystyrene) using 2-phenyl-2-cyanoethyl chloroformate. A photoresist material consisting of the copolymer and bis[[(2-nitrobenzyl)-oxy] carbonyl]-4,4′-trimethylenedipiperidine used as an amine photogenerator affords positive tone images by UV irradiation. The effect of copolymer structure and composition on imaging, thermal stability, and the ease of β-elimination reaction is discussed. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3543-3552 1997
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Preparation of porous hydrophilic monoliths: Effect of the polymerization conditions on the porous properties of poly (acrylamide-co-N,N′-methylenebisacrylamide) monolithic rods (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 1013-1021 
    Details
    ISSN: 0887-624X
    Keywords: macroporous monoliths ; acrylamide copolymers ; polymerization in mold ; porogens ; polymerization kinetics ; porous properties ; morphology ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molded macroporous monoliths with pores sizes up to 1000 nm have been prepared by copolymerization of the hydrophilic monomers, acrylamide, and N,N′-methylenebisacrylamide, in the presence of a porogenic diluent. A combination of dimethylsulfoxide and 2-heptanol was selected from a broad spectrum of solvents and water soluble polymers to achieve the optimum composition of the porogenic mixture. In addition to the composition of the porogen the porous properties of the monolithic rods can also be optimized through changes in the percentage of both N,N′-methylene-bisacrylamide (crosslinking monomer) and azobisisobutyronitrile (free radical initiator) used for the polymerization. The hydrophilic monoliths may be used in the separation of biological polymers, solid-phase extraction, or for immobilization of proteins. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 1013-1021, 1997
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Chromatography of functional polymers: A new approach to the characterization of reactive polymers obtained by chemical modification (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 1173-1180 
    Details
    ISSN: 0887-624X
    Keywords: chemical composition distribution ; liquid chromatography ; porous polymer beads ; HPLC ; monodisperse particles ; poly(isobutylene-co-4-methylstyrene) ; bromination ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High-performance liquid chromatography (HPLC) has been used to complement size-exclusion (gel permeation) chromatography (SEC) for the characterization of functional polymers. Whereas SEC is unable to detect compositional changes, HPLC in an appropriate interacting medium can provide detailed information on compositional changes occurring during chemical modification of a polymer. The method has been demonstrated using a normal-phase column consisting of porous monodisperse 10 μm poly(2,3-dihydroxypropyl methacrylate-co-ethylene dimethacrylate) beads that have a homogeneous coverage of aliphatic hydroxyl groups for the analysis of brominated poly(isobutylene-co-4-methylstyrene). Differences of well below 1 mol % of bromomethylstyrene units are easily detected and quantified. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1173-1180, 1997
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Preparation and functionalization of reactive monodisperse macroporous poly(chloromethylstyrene-co-styrene-co-divinylbenzene) beads by a staged templated suspension polymerization (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 2631-2643 
    Details
    ISSN: 0887-624X
    Keywords: macroporous beads ; poly(chloromethylstyrene) ; chiral separation ; HPLC ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactive monodisperse porous poly(chloromethylstyrene-co-styrene-co-divinylbenzene) beads have been prepared by a staged templated suspension polymerization method with different concentrations of linear polystyrene porogen and chloromethylstyrene in the polymerization mixture. The presence of a small amount of linear polystyrene in the polymerization mixture leads to a dramatic increase in both the pore size and the pore volume of the resulting beads. In contrast, addition of chloromethylstyrene leads to lower surface areas and smoother surfaces due to the reduced compatibility between the polystyrene porogen and the newly formed crosslinked chains. The modification of chloromethylstyrene beads by Gabriel synthesis to obtain aminated beads has also been studied. The final number of primary amino groups is related to the starting concentration of functional benzyl chloride moieties rather than to the porous properties. Both π-basic and π-acidic type chiral selectors, (R)-1-(1-naphthyl)-ethylamine and (R)-N-(3,5-dinitrobenzoyl)phenylglycine, respectively, have been attached to the amino functionalized beads, and the resulting chiral beads have been used in the model HPLC separations of enantiomers. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2631-2643 1997
    Additional Material: 6 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Influence of the seed polymer on the chromatographic properties of size monodisperse polymeric separation media prepared by a multi-step swelling and polymerization method (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 2129-2141 
    Details
    ISSN: 0887-624X
    Keywords: multi-step swelling and polymerization method ; size monodisperse particles ; separation media ; polymeric porogen ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monodisperse polymer particle-based separation media were prepared by a multi-step swelling and polymerization method with two pairs of monomers and two porogenic solvents. Their chromatographic properties were compared to those of beads prepared by a corresponding suspension polymerization method without the use of seed polymer to ascertain the influence of the seed polymer on their porous structures. A large change in porous structure was observed when the swollen particle consisting of monomers and porogenic solvents contained at least one good solvent for the polystyrene seed polymer, allowing it to remain in the polymerizing medium. In contrast, when the polystyrene seed particle was excluded from the swollen oil droplets, due to its poor solubility in the monomers and the porogenic solvents, there was no difference in the chromatographic properties such as pore volume, pore size, pore size distribution, or retention selectivity between the multi-step swelling and polymerization method and the suspension polymerization method. Since the only difference between the multi-step swelling and polymerization method and the suspension method is the use of the seed polymer, it appears that a very small amount (〈 1% v/v) of seed polymers in the enlarged swollen droplets plays an important role as a porogen and affects the porous structure as well as the chromatographic properties of the monodisperse polymer particle-based separation media. © 1993 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080310819
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  • 8
    Electronic Resource
    Electronic Resource
    Fine control of the porous structure and chromatographic properties of monodisperse macroporous poly(styrene-co-divinylbenzene) beads prepared using polymer porogens (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2577-2588 
    Details
    ISSN: 0887-624X
    Keywords: poly(styrene-co-divinylbenzene) beads ; macroporous polymer ; porous properties ; polymeric porogen ; monodisperse beads ; chromatographic packing ; reversed-phase chromotagraphy ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The porous structure of monodisperse macroporous beads can be controlled by using soluble polymers with well-defined structural characteristics as part of the porogenic mixture. In general, the use of linear polystyrene as a porogen in the preparation of poly (styrene-co-divinylbenzene) beads shifts the pore size distribution towards larger pores. While a direct correlation between pore size and molecular weight of the porogen has been established, the chemical composition of the polymer porogen has no effect on the porous and chromatographic properties of the beads. These findings suggest that the average molar volume of the porogenic system is important while the miscibility of the polymer porogen with the crosslinked polymer that is formed is of little relevance. © 1994 John Wiley & Sons, Inc.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080321321
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  • 9
    Electronic Resource
    Electronic Resource
    Monodisperse polymer beads as packing material for high-performance liquid chromotography: Effect of divinylbenzene content on the porous and chromatographic properties of poly(styrene-co-divinylbenzene) beads prepared in presence of linear polystyrene as a porogen (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2169-2175 
    Details
    ISSN: 0887-624X
    Keywords: poly(styrene-co-divinylbenzene) beads ; macroporous polymer ; monodisperse beads ; porous properties ; divinylbenzene content effect ; chromatographic evaluation ; high-performance liquid chromatography ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of concentration of divinylbenzene on pore size distribution and surface areas of micropores, mesopores, and macropores in uniformly sized porous poly(styrene-co-divinylbenzene) beads prepared in the presence of linear polystyrene as a component of the porogenic mixture has been studied. While the total specific surface area was clearly determined by the content of divinylbenzene, the sum of pore volumes for mesopores and macropores as well as their size distribution does not change within a broad range of DVB concentrations. Consequently, the size exclusion chromatography calibration curves are almost identical for all the beads prepared with different percentages of crosslinking monomer. However, the more crosslinked beads have better mechanical and hydrodynamic properties. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080321120
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  • 10
    Electronic Resource
    Electronic Resource
    Preparation of colored poly(styrene-co-butyl methacrylate) micrometer size beads with narrow size distribution by dispersion polymerization in presence of dyes (1995)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 2961-2968 
    Details
    ISSN: 0887-624X
    Keywords: dispersion polymerization ; styrene ; butyl methacrylate ; dyes ; colored mono-disperse beads ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation of monodisperse polymer particles formed by a dispersion copolymerization of a system containing styrene, butyl methacrylate, and nonpolymerizable dyes has been studied. Both the polarity of the ethanol-water dispersion medium and the polymerization rate were found to have a significant effect on the particle size. Experimental conditions have been determined that enable the preparation of colored beads having a narrow size distribution. While the benzoyl peroxide initiated polymerization is seriously inhibited by the presence of dyes, polymerization with azobisisobutyronitrile in presence of the black dye Nigrosin affords monodisperse beads in a high yield. © 1995 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1995.080331714
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