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  • 1
    Electronic Resource
    Electronic Resource
    Size-exclusion and high-performance precipitation liquid chromatography of styrene-acrylonitrile copolymers (1984)
    s.l. : American Chemical Society
    Macromolecules 17 (1984), S. 962-967 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma00134a072
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  • 2
    Electronic Resource
    Electronic Resource
    The analysis of synthetic organic materials—A review (1991)
    Springer
    Microchimica acta 104 (1991), S. 215-223 
    Details
    ISSN: 1436-5073
    Keywords: synthetic organic materials ; characterization of solid-state polymers ; X-ray photoelectron spectroscopy ; mass spectrometry of polymers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Synthetic organic materials consist of polymers, low-molecular-weight additives, and fillers. The review deals with the characterization of the polymer portion in the solid state by inelastic interactions with X-rays and by mass spectrometry (MS). Field desorption MS, secondary ion MS, fast atom bombardment MS, and plasma desorption MS have been used in a molar mass range up to 50000 g/mol. Electrospray or laser desorption MS enable samples of even higher molar mass to be investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01245509
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  • 3
    Electronic Resource
    Electronic Resource
    Investigation of copolymers of styrene and ethyl methacrylate by size exclusion chromatography and gradient HPLC (1987)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 328 (1987), S. 76-81 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Copolymers of styrene and ethyl methacrylate have been separated according to composition by gradient HPLC on silica columns or CN bonded phase columns. This mode of separation according to composition was applied to fractions obtained by size exclusion chromatography (SEC). From viscosity and molecular mass data of copolymers with a styrene content ranging from 7.5 to 95.3 mass-% it can be concluded that SEC separates mainly by molecular mass even in this copolymer system. Thus, chromatographic cross-fractionation is possible by prefractionation by SEC and subsequent separation according to composition by gradient HPLC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00560954
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  • 4
    Electronic Resource
    Electronic Resource
    Micellization of a radial copolymer with four polystyrene-block-polybutadiene branches (1984)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 1187-1197 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Similarly to the three-block copolymer poly(styrene-b-butadiene-b-styrene), a radial block copolymer with four brances consisting of inner polybutadiene and outer polystyrene blocks forms, in a mixed solvent tetrahydrofuran/ethanol, spherical micelles with a polybutadiene core and polystyrene shell. The equilibrium between these micelles and the molecularly dissolved copolymer was studied as a function of the solvent composition by means of light scattering, sedimentation velocity, and GPC. The sedimentation diagrams were interpreted taking into account the Gilbert theory of mobile equilibrium in systems of associating macromolecules.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1984.021850612
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  • 5
    Electronic Resource
    Electronic Resource
    Chromatographic cross-fractionation of statistical copolymers of styrene and 2-methoxyethyl methacrylate (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 427-435 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Chromatographic cross-fractionation (CCF) by preparative size-exclusion chromatography (SEC) and gradient high-performance liquid chromatography was applied to stat-copoly-(styrene/2-methoxyethyl methacrylate). Two specimens were analyzed, which had been polymerized from the same batch of monomer mixture in benzene solution to either low or high conversion (10,1 or 86,4 mass-%, respectively). The initial monomer mixture contained more styrene (76,7 mass-%) than the azeotropic one (39,4%). The integral chemical composition distribution (CCD) of the low-conversion sample agreed with the theoretical curve, whereas the calculated CCD of the high-conversion specimen was broader than the one determined experimentally. The contour map of the low-conversion sample exhibited the tapering effect of molar mass predicted by theory. The corresponding map of the high-conversion sample showed that the composition shift towards the initial monomer ratio induced production of macromolecules of higher molar mass.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900221
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  • 6
    Electronic Resource
    Electronic Resource
    Investigation of copolymers of styrene and ethyl methacrylate by size-exclusion chromatography and gradient HPLC (1988)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 330 (1988), S. 46-49 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Copolymers of styrene and ethyl methacrylate (SEMA) have been separated according to composition by reversed-phase chromatography on C18 columns. The starting eluent was methanol, in which the copolymers are insoluble, and an elution gradient was formed by the addition of tetrahydrofuran, which is less polar than methanol yet a good solvent for SEMA copolymers. The method was applied to fractions obtained by size exclusion chromatography of model mixtures, and yielded a separation superior to that obtained in normal-phase mode on polar columns using gradients of increasing polarity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00494534
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  • 7
    Electronic Resource
    Electronic Resource
    Nichtadditivität von Brechungsindexinkrementen bei Copolymeren mit N-Phenylmaleimid (1993)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 206 (1993), S. 121-139 
    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: Refractive index increments of copolymers of N-phenyl maleimide with styrene, methyl methacrylate and acrylonitrile, and of the corresponding homopolymers were measured in different solvents at 536 nm and 25°C. In contrast to the usually observed behaviour, the refractive index increments of the copolymers with styrene and methyl methacrylate exhibit positive deviations from additivity in all solvents used. This result was confirmed by independent measurements of the partial specific volumes. Possible reasons for nonadditivity are discussed.
    Notes: Brechungsindexinkremente der Copolymeren von N-Phenylmaleimid mit Styrol, Methylmethacrylat und Acrylnitril sowie der entsprechenden Homopolymeren wurden in verschiedenen Lösungsmitteln bei 536 nm und 25°C gemessen. Die Brechungsindexinkremente der Copolymeren mit Styrol und Methylmethacrylat zeigten in allen verwendeten Lösungsmitteln positive Abweichungen von der für die meisten Copolymeren üblichen Additivität. Dies wurde durch unabhängige Mesungen der partiellen spezifischen Volumina bestätigt. Mögliche Ursachen der Nichtadditivität werden erörtert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1993.052060112
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  • 8
    Electronic Resource
    Electronic Resource
    Separation of stat-copoly(styrene/2-methoxyethyl methacrylate) samples according to composition by gradient high-performance liquid chromatography (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 3147-3161 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Statistical copolymers of styrene (S) and 2-methoxyethyl methacrylate (MEMA) (13-87 mass % of the latter monomer) were investigated by gradient HPLC on columns with either silica or CN-bonded phase packings. The samples were injected in THF solution. The starting eluent was in each case a nonsolvent (isooctane or mixtures of isooctane with THF and methanol). Separation was achieved by increasing the concentration of THF or methanol in the eluent. A calibration mixture of four copolymers (26, 49, 62, and 87% MEMA) was investigated according to the principles of chromatographic cross-fractionation (CCF) by size exclusion chromatography and subsequent gradient HPLC. The influence of molar mass on HPLC retention was small and, for the samples investigated by CCF, independent of copolymer composition. The composition effect on detector signal was also studied. At 230 nm wavelength and with MEMA content in the range between 20 and 40%, the effect was small and caused the average composition calculated from CCF results to deviate from the directly measured value by not more than 0.2 or 0.8% for the two copolymers investigated.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070371107
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  • 9
    Electronic Resource
    Electronic Resource
    Gradient high-performance liquid chromatography of statistical and block copolymers of styrene and t-butyl methacrylate (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 38 (1989), S. 1761-1774 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Copolymers of styrene (S) and tert-butyl methacrylate (TBMA) containing 24-92 mass % of the latter monomer were investigated using a silica column with isooctane/tetrahydrofuran (THF) gradients and on a phenyl bonded-phase column by methanol (MeOH)/THF gradients using UV detection. In both cases, retention decreased with increasing TBMA content of the sample. This is in contrast to the behavior of copolymers of S and methyl methacrylate (MMA) whose retention in gradient elution on silica columns increases with MMA content due to the polarity of this unit. The inversion of elution order is a result of the bulky TBMA residues shielding the polar groups of the ester units. For copolymers of varying composition, the gradation in retention on retention on silica is quite sufficient for separating S/MMA but not for S/TBMA mixtures. The latter could be separated by composition on phenyl packings through MeOH/THF gradient elution. Block copolymers containing 80 or 92% TBMA could be baseline-separated. It was also possible to separate these samples from admixed PTBMA or PS homopolymers. Under the conditions used, the retention of a given block copolymer was somewhat higher than that of a statistical copolymer having the same composition. A block copolymer containing 80% TBMA was converted by transesterification into a S/MMA block copolymer. The elution of the latter fitted well in the sequence of S/MMA copolymers on silica column.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070380914
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  • 10
    Electronic Resource
    Electronic Resource
    Charakterisierung von styrol-acrylnitril-copolymeren durch ausschlußchromatographie und turbidimetrische titration der dabei erhaltenen fraktionen. II. Untersuchung einer probe mit breiter chemischer verteilung (1985)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 130 (1985), S. 41-54 
    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: A sample of poly(styrene-co-acrylonitrile) with about 40% (mol/mol) acrylonitrile was analysed by means of turbidimetric titration (TT), size exclusion chromatography (SEC), TT of SEC-fractions, and high performance precipitation chromatography (HPPLC) of SEC-fractions. While TT and SEC of the crude copolymer only showed broad but apparently homogeneous distributions in size and composition, cross-analyses (TT of SEC-fractions/HPPLC) revealed the presence of three rather different components. This result was found by the of SEC-fractions with n-hexane as a precipitant and only subsequently established by HPPLC using gradient elution with n-hexane and tetrahydrofuran as components. A topographic composition map of the copolymer sample under investigation is given.
    Notes: Eine Probe eines Styrol-Acrylnitril-Copolymeren mit etwa 40 mol-% Acrylnitril wurde mit Hilfe der Trübungstitration (TT), der Ausschlußchromatographie (SEC), der TT von SEC-Fraktionen und der Hochdruck-Fällungschromatographie (HPPLC) der SEC-Fraktionen untersucht. Während die TT und die SEC für das unfraktionierte Copolymere zwar breite, aber scheinbar homogene Verteilungen nach der Molmasse und der Zusammensetzung lieferten, offenbarten Kreuzuntersuchungen (TT von SEC-Fraktionen/HPPLC) das Vorliegen von drei ziemlich unterschiedlichen Komponenten. Dieses Ergebnis wurde zuerst durch die TT der SEC-Fraktionen mit n-Hexan als Fällungsmittel gefunden. Nachfolgend wurde es mit der HPPLC unter Verwendung eines Elutionsgradienten mit n-Hexan und Tetrahydrofuran als Komponenten bestätigt. In einem topographischen Bild wurde die Zusammensetzung der untersuchten Copolymerprobe dargestellt.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1985.051300103
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