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  • 1
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    Response to "Comment on Once-broken wormlike macromolecules" (1984)
    American Chemical Society
    Details
    Publication Date: 1984-10-01
    Print ISSN: 0024-9297
    Electronic ISSN: 1520-5835
    Topics: Chemistry and Pharmacology , Physics
    Published by American Chemical Society
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    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    Response to "Comment on Once-broken wormlike macromolecules" (1984)
    s.l. : American Chemical Society
    Macromolecules 17 (1984), S. 2206-2206 
    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/ma00140a058
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  • 3
    Electronic Resource
    Electronic Resource
    Venetzung von Amylose mit Epichlorhydrin, 1. Untersuchung der Phase vor der Gelbildung (1978)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 179 (1978), S. 1465-1483 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Cross-linking of amylose with 1-chloro-2,3-epoxypropane (epichlorohydrin) was studied in aqueous 1M NaOH solution in dependence of the amylose concentration, the mole ratio of anhydroglucose to epichlorohydrin, and the degree of polymerization of the primary chains. Structural changes which occur during the pre-gel phase were followed by chemical analysis, by viscosity and light scattering measurements, and by the optical properties of the iodine complex. The results indicate in the early stage of the process that the introduced glycerol diether groups are mainly present as intermolecular cross-links as seen from a rapid increase in the molecular weight. With further progress of the reaction a decrease of particle density may be derived from the unusual dependence of intrinsic viscosity and mean square radii of gyration on molecular weight. The results are discussed being due to association of amylose segments by hydrogen bonds in the weakly cross-linked products and a solubilizing effect of monoether substituents introduced later on.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1978.021790606
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  • 4
    Electronic Resource
    Electronic Resource
    Chemische synthese verzweigter polysaccharide, 7.6. Mitteilung: cf.1. Zur frage des abbaus der polysaccharid-hauptkette bei verzweigung über glykosidische bindungen (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 1183-1199 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 6-Trityl-2,3-dicarbanilyl and 2,3-dicarbanilyl derivatives of amylose and cellulose have previously been used as a backbone to introduce oligosaccharide branches by (1 → 6) glycosidic bonds. Possible degradation prior and during the glycoside coupling was now followed by light scattering measurements on each step of derivatization. The results obtained with derivatives of technical and synthetic amyloses indicate that some degradation may occur in the tritylation reaction and possibly in the conversion to the 6-trityl-2,3-dicarbanilate. In the following steps, e.g. detritylation and glycosidic condensation of glucose and maltose derivatives under the conditions applied, degradation appears to be almost absent. In corresponding studies with cellulose derivatives problems arise mainly in the tritylation step. The results of the light scattering and viscosity measurements are discussed with respect to the molecular conformation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021800507
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  • 5
    Electronic Resource
    Electronic Resource
    Chemische synthese verzweigter Polysaccharide, 8.7. Mitteilung: cf.1. Vergleichende struckturuntersuchungen an amylose- und Cellulosederivaten mit verschiedenen Substituenten an C-6 durch optische Rotationsdispersion und circular-dichroismus (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 1201-1213 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Carbanilated and tritylated derivatives of amylose and cellulose previously studied by light scattering were further characterized by measurement of optical rotatory dispersion (ORD) and circular dichroism (CD). No anomalous ORD and only a weak CD was found for 6-tritylamylose in 1,4-dioxane, indicating a widely unordered structure which is in accordance with the low viscosity of the compound. In comparison with the other carbanilated derivatives having substituents in C-6 position, i.e. trityl-, carbanilyl- or glucosyl groups, 2,3-dicarbanilylamylose is distinguished by an especially high Cotton effect. This result suggests a helical chain, -  clearly visible by excition splitting - , that may adopt a more regular orientation in case of free C-6 hydroxyl groups, whereas trityl-, carbanilyl-, and glucosyl groups almost equally will contribute to a lower state of orientation. Conversely in the cellulose derivatives a clear steric dependence on the size of the C-6 substituent was found. The increase of the Cotton effect observed for the bulky trityl group may arise from the β(1 → 4) linkage that causes an alternating or syndiotactic like structure in cellulose, which is more sensitive to restrictions of the free rotation due to steric effect. In addition, viscosity and optical rotation in NMP and 1,4-dioxane were measured in the range of 20 to 70°C. An unusual behaviour is observed for 6-trityl-2,3-dicarbanilylamylose in NMP indicating a conformation transition near 45°C, and is discussed in connection with the findings from light scattering measurements.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021800508
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  • 6
    Electronic Resource
    Electronic Resource
    Chemische synthese verzweigter polysaccharide, 109. Mitteilung: cf.6.. Polymere mit amidartig gebundenen mono- und oligosaccharid-seitenkettenHerrn Professor Dr. H.-J. Cantow zum 60. Geburtstag gewidmet (1983)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 184 (1983), S. 1441-1458 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Binding of mono-, di-, and oligosaccharides by amide linkage to polymers carrying carboxylic or amino groups was studied with synthetic polymers (poly(acrylic acid), poly(vinylamine)) and polysaccharide derivatives (e.g. chitosan). Suitable methods are described which allow a variation of the number and lenght of the attached saccharide branches. In the absence of salt, all products with a degree of substitution (DS) 〈 1 show polyelectrolyte behaviour. Compared with the unsubstituted polyelectrolytes, for the branched polymers a substantial increase of the viscosity was observed within a certain range of branch density. In the case of glucose side chains, the maximum viscosity was found near DS = 0,1. In the case of maltose side chains, this maximum of the viscosity occurred at higher DS. A similar but smaller increase in the viscosity was observed in 0,1 M NaCl solution. The results are explained by a shielding of the backbone charges from the counterions and by an additional chain stiffening effect resulting from hydrogen bonds, i.e., ring formation between the amide linkage and adjacent free carboxylic or amino groups.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1983.021840711
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  • 7
    Electronic Resource
    Electronic Resource
    Polyanion-polykation-komplexe mit saccharid-substituierten polyacrylsäuren und polyvinylaminenHerrn Prof. W. Burchard mit herzlichen Wünschen zum 60. Geburtstag gewidmet (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 1219-1230 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Samples of saccharide-substituted poly(acrylic acid) and polyvinylamine varying in DS and length of the saccharide side chains were investigated with regard to their polyelectrolyte character by determining their pK0a values and by a potentiometric, conductometric and turbidimetric titration with an oppositely charged polyelectrolyte. Criteria employed for the evaluation of these “symplex titrations” were the ratio of cationic to anionic groups at the endpoint and the course of the turbidimetric curve classified according to several schematized curve types. From the results obtained it can be concluded that substitution by saccharide side chains in the case of poly(acrylic acid) impedes Coulombic interaction to some extent only by steric hindrance, while in the case of the substituted polyvinylamines also intermolecular H-bonds between the amino groups and the saccharide side chains have to be taken into account.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021910601
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  • 8
    Electronic Resource
    Electronic Resource
    Amphiphilic properties of synthetic glycolipids based on amide linkages, 4.Part 3: cf. ref.1. 13C NMR spectroscopic studies on the gelation of N-octyl-D-gluconamide in aqueous solution (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 3097-3106 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 13C NMR measurements were taken on cooling of aqueous solutions of N-octyl-D-gluconamide to follow the process of gelation. On cooling from 90°C gelation sharply occurs at 60-62°C. In the pre-stage of gelation at 64°C an aggregated species, probably a dimeric form of octylgluconamide, is detected. Additional signals for sugar carbons C-1, C-4 and C-6 indicate hydrogen bonding. As a side reaction conversion of the octylgluconamide to the ammonium salt takes place. Assignments of the new signals were made with the ammonium salt formed from D-gluconamide and the corresponding octylammonium salt of gluconic acid. When the solution of octylgluconamide is kept at 64°C for a longer period, octylgluconamide, free and aggregated, and its ammonium salt coexist. At 64°C relaxation times t1 of the sugar carbons corresponding to the octylgluconamide species are much shorter than those of the salt, indicating a decrease of the mobility of the sugar carbons of the former in the pre-stage of gelation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021911228
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  • 9
    Electronic Resource
    Electronic Resource
    Linear and star-shaped hybrid polymers, 3Part 2: cf. 1.. An improved purification procedure for coupling products of oligosaccharides by amide linkage (1984)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 1855-1866 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A convenient method for binding saccharides to natural and synthetic substances, polymers and low molecular weight compounds, consists in coupling via an amide linkage. For this purpose aldonolactone or amino groups are introduced at the reducting end of the saccharides which allows coupling to a great variety of amino and carboxyl groups containing compounds. Purification with the usual ion-exchange resins based on polystyrene proved unsatisfactory for oligosaccharides due to adsorption effects and reduced ion-exchange capacity. Excellent results on each step of conversion are obtained by chromatography on a cross-linked poly(acrylamide) gel (Bio-Gel P-4 and P-10) containing a small amount of carboxylic groups introduced by moderate saponification. The new procedure combining the effect of molecular size fractionation and ion-exchange chromatography offers a wide field of application.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1984.021850908
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  • 10
    Electronic Resource
    Electronic Resource
    Amphiphilic properties of synthetic glycolipids based on amide linkages, 3Part 2: cf.1. Temperature and concentration dependence of the reduced viscosity of gel-forming alkyl gluconamidesDedicated to Prof. H.-J. Cantow on the occasion of his 65th birthday (1988)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 189 (1988), S. 2433-2442 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In order to follow the process of aggregation, viscosity measurements in dilute aqueous solution were performed with two carbohydrate amphiphiles: (i) N-octylgluconamide (C8-GA) and (ii) N-decanoyl-N-methylglucamide (C10-MGA). Both compounds ten to form a gel on cooling, the former at 65°C, the latter at 10°C. Electron micrographs have shown that the gels are composed of a loose network of thin, regularly twisted helical ropes. By viscosity measurements over a wide range of temperatures and concentrations, typical changes of the reduced viscosity were observed. Results are discussed with respect to the critical micelle concentration (CMC), the Krafft point, i. e. the critical temperature of crystallization (Tc), and the cloud point (Tcp). It is concluded that micellar aggregation to rod-shaped particles, quasi-crystalline aggregation to highly hydrated gels, and crystallization of monomers, the latter mediated by hydrogen bonding, are involved and compete with each other.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1988.021891021
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