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  • 11
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2239-2246 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of acrylonitrile (r1) and p-acetoxystyrene (r2) in bulk yields reactivity ratios r1 = 0.08 and r2 = 0.42. Crosslinked resins are readily obtained by a new type of precipitation copolymerization of acrylonitrile, p-acetoxystyrene, and divinylbenzene. After deacetylation, the phenolic groups afford useful attachment sites for protected amino acids as a first stage in solid-phase peptide synthesis. Reactivity of typical 10% functionalized polyacrylonitrile-based resins is comparable to that of the more usual polystyrene-based equivalents, although swelling characteristics of the two types of resin are very different.
    Additional Material: 3 Ill.
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  • 12
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2281-2291 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Macosko-Miller approach is used to obtain an expression for the polydispersity index for AA, BB, CC linear step polymerization system in which B and C are the same type of functional group. The dependence of the polydispersity index, as a function of the extent of reaction, on the monomer masses and on the relative reactivities of B and C groups toward A, is examined in detail.
    Additional Material: 8 Ill.
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  • 13
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2307-2322 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The various kinds of molecular defect that are related to the thermal property of polyacrylonitrile (PAN) are studied in detail in relation to the polymerization mechanism in an aqueous medium. The existence of two different kinds of polymer radical is pointed out and the significance of polarity of radical species is emphasized. It is shown that the structural irregularity along the main chain is surely present but has little effect on the thermal property of PAN. It is estimated that one of the most significant defects relating to the thermal property is the main-chian type of branching the occurs predominantly in hydrogen on a polymer backbone. The relationship between activator (i.e., NaHSO3) incorporation and branch inhibition mechanisms is discussed. The optimum polymerization condition, under which the highest thermal quality of molecules is obtained, is found empirically within a limited experimental range, for an aqueous heterogeneous system.
    Additional Material: 12 Ill.
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  • 14
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2333-2346 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of chloromethylated polystyrene with methyl(2- hydroxyethyl)amine and butyle (2-hydroxyethyl)amine was studied kinetically. The reaction of benzyl chloride with these amines was also investigated for comparison. N,N-dimethylformamide and dioxane were used as solvents. The reactions of benzyl chloride with the two amines in these solvents took place according to normal kinetics of the second order. Reaction kinetics depend on the nature of the amine and solvent in Chloromethylated polystyrene reactions. In dioxane the self-accelerating effect of the reaction for β ≃ 0.5 is apparent. Steric hindrance of the reaction, beginning with a conversion degree of about 75%, wss observed for butyl(2-hydroxyethyl)amine in N,N-dimethylformamide. This self-accelerating effect is observed in dioxane at the same reaction degree. The activation energies and frequency factors were calculated for the amination of benzyl chloride and chloromethylated polystyrene with the two amines in N,N-dimethylformamide and dioxane.
    Additional Material: 10 Ill.
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  • 15
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2391-2410 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Methyl-5-vinylpyridine-N-oxide, 4-vinylquinoline-N-oxide. 9-vinylacridine-N-oxide, p-N,N-dimethylaminostyrene-N-oxide units were introduced in polymeric chains as homopolymers or/and as styrene copolymers to study their photocrosslinking. The method used for characterization of photocrosslinked films was a “photoresist test” described in Part I of this series. The photosensitivity of the different chromophores bound to the different polymer has also been studied by UV, IR, and fluorescence spectrophotometries. The use of aromatic amine N-oxide groups in polymers seems to be a general means to produce their photocrosslinking by radical reactions. Among the different polymeric materials prepared, 4-vinylpyridine-N-oxide and 4-vinylquinoline-N-oxide are the most photosensitive.
    Additional Material: 14 Ill.
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  • 16
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2437-2449 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymorphic behavior and γ-ray-initiated postpolymerization of the even-numbered long-chain Methacrylates (C18-C12) have been investigated. Phase transition behaviors of octadecyl, hexadecyl, tetradecyl, and dodecyl methacrylates are respectively, which become simpler with shortening of the chain length. The methacrylate monomers with sufficiently long hydrocarbon chains, such as octadecyl and hexadecyl, can be polymerized rapidly in the α-form crystal (hexagonal packing) by a fully two-dimensional mechanism, whereas in the β-form crystal (triclinic packing), polymerization can hardly occur. In the case of dodecyl methacrylate, however, an accelerated polymerization in the β form occurs after an induction period of several hours and the resultant polymer is gel-like. This can be interpreted by the propagation reaction across the polymer chain already formed. It has been found that the solid-state post-polymerization of n-alkyl methacrylates is affected by the chain length through the packing mode of the monomer molecules and also by the aggregation state of side chains in the resultant comblike polymer.
    Additional Material: 9 Ill.
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  • 17
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of epoxy groups at the surface layer of ethyl acrylate-glycidyl methacrylate copolymer (1) emulsion particles on its crosslinking reactivity has been investigated. For this purpose two series of I emulsions were prepared. In the Y series, of which emulsion particles have epoxy groups at the surface layer, the epoxy content in the polymerization recipe was varied. For preparing the X series, of which emulsion particles have few epoxy groups at the surface layer, the high epoxy content of a given emulsion was reduced by various degrees of cleavage reaction with HCl-CaCl2. In emulsion blend films with amine-group-containing copolymer (II) emulsion, where the crosslinking reaction was expected to proceed only at the interfacial layer of I and II emulsion particles, the Y series, compared to the X series at the equal overall epoxy content in particles, showed less swelling and higher gel fraction in dioxane, less swelling in water, and higher tensile strength and modulus. On the other hand, this difference was not observed in the next two crosslinked films in which crosslinking was expected to be homogeneous. First, blends of I and II, which were isolated from the corresponding emulsions discussed above, were cast from dioxane solutions. Second, I emulsions were cast with BF3 ether complex which was expected to penetrate into the particles. It is concluded that the response of I emulsion cleaving the epoxy groups at the surface layer of particles to subsequent interfacial crosslinking is obviously reduced. However, even such an emulsion can be crosslinked to an extent similar to that of an uncleaved emulsion with similar overall epoxy content, if the crosslinking reaction is conducted so as to give an homogeneous effect.
    Additional Material: 8 Ill.
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  • 18
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ammonia used as both reactant and solvent has been shown to dehydrochlorinate 1,1,1-tri-chloro-2,2-bis(4-hydroxyphenyl)ethane smoothly to 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene. The reaction is complete in 1 hr at 100°C, and after two crystallizations from methanol/water affords polymerizable quality monomer for the synthesis of highly flame-resistant polycarbonates. The use of organic solvents in combination with ammonia does not offer any rate advantages over pure ammonia. Primary and secondary amines also can be used to effect the dehydrochlorination but, except for the methylamine, are significantly less reactive and lead to less pure product than amonia.
    Additional Material: 4 Ill.
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  • 19
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2513-2521 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of p-benzoquinone with tin tetrachloride in the absence of solvents was investigated by isolation and identification of the reaction products. This reaction leads to the formation of polymeric quinone-tin derivatives free from combined chlorine, chlorinated quinones, quinhydrone, and minute amounts of CI2 and HCI gases. The tin content varies accroding to the molar ratios of the reactants and reaches its maximum (72%) at the smallest SnCI4 ratio. The existence of the Sn-Sn bond in the polymeric derivatives was confirmed chemically and spectroscopically. A mechanism based on the formation of radical intermediates which can account for the reaction products was developed. In view of their quinonoid nature, high thermal stability, and the presence of Sn-Sn bonds, the polytin derivatives are to be investigated as radical traps in the stabilization of polymeric arcticles against radical degradation process.
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  • 20
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2523-2533 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymeric p-benzoquinone-tin derivatives obtained from the reaction of p-benzoquinone with tin tetrachloride in the absence of solvent have been investigated as thermal stabilizers for rigid PVC at 200°C by measuring the rate of dehydrochlorination. The results reveal the greater stabilizing efficiency of the investigated products in relation to dibutyltin maleate and the basic lead stabilizers commonly used in industry. Evidence has been accumulated that the quinone and metallic elements (Sn—Sn bonds) of the stabilizer participate in the stabilization process by trapping the radical intermediates of degradation and blocking the odd electron sites formed on the polymer chains. Although stabilizers with high quinone content provide greater stabilization in the early stages of degradation, their efficiency sharply decreases in subsequent stages. On the other hand, stabilizers of high tin content effectively prohibit the dehydrochlorination reaction at all stages of degradation. On an equivalent basis of metal content, the results clearly demonstrate the greater stabilizing efficiency of tin atoms when found in direct contact in the stabilizer molecule. The mechanism of stabilization suggested to account for the results obtained may be considered as additional evidence in support of the radical nature of the dehydrochlorination reaction.
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