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  • 1
    Electronic Resource
    Electronic Resource
    Kinetics of emulsion copolymerization. II. Effect of free radical desorption on the rate of emulsion copolymerization of styrene and methyl methacrylate (1982)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 27 (1982), S. 2483-2501 
    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: The rate coefficient for radical desorption from the polymer particles is derived for an emulsion copolymerization system, assuming, for simplicity, that only monomer radicals can desorb from the particles. The effect of free radical desorption on the rate of emulsion copolymerization and the copolymer composition is theoretically analyzed, using the rate coefficient for radical desorption developed in this paper and a mathematical reaction model proposed earlier by the present authors for an emulsion copolymerization system where the average number of total radicals per particle does not exceed 0.5. The validity of the analysis is demonstrated experimentally using the seeded emulsion copolymerization of styrene (ST) and methyl methacrylate (MMA). Radical desorption from the particles does not affect the copolymer composition, but the desorption of MMA - monomer radicals plays an important role in determining the rate of emulsion copolymerization, while the desorption of ST - monomer radicals from the particles can be neglected from a kinetic point of view.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1982.070270719
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  • 2
    Electronic Resource
    Electronic Resource
    Computational examination of the electrophilic reaction on oxidative polymerization of phenyltrimethylsilane with sulfur chloride (1993)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 4 (1993), S. 12-16 
    Details
    ISSN: 1042-7147
    Keywords: Cationic oxidative polymerization ; MNDO-PM3 ; Phenyltrimethylsilane ; Poly(phenylene sulfide) ; Sulfur chloride ; HOMO ; 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
    Notes: Phenyltrimethylsilane possesses a higher HOMO energy (-9.34 eV) than nonsubstituted benzene (〉0.41 eV). The π electron of the phenyltrimethylsilane localizes on the benzene ring at the ipso position rather than at the para position. Two center energies calculated by the MNDO-PM3 method indicate that the C—Si bond is facilitated to cleave in comparison with the C—H (para position) one of the benzene ring. Phenyltrimethylsilane and phenyl bis(trimethylsilane) were polymerized with sulfur chloride through the cationic oxidative polymerization. The product is isolated as oligo(p-phenylene sulfide), with a melting point of 150-190°C. An electrophile attacks the carbon atom linked to the Si atom in phenyltrimethylsilane. The new synthetic route of PPS can be established on the basis of the computational calculation.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1993.220040103
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  • 3
    Electronic Resource
    Electronic Resource
    Synthesis of poly(sulfonium cation) as an alkylating reagent (1994)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 5 (1994), S. 507-512 
    Details
    ISSN: 1042-7147
    Keywords: Poly(sulfonium cation) ; Alkylating reagent ; Demethylation ; Poly(phenylene sulfide) ; 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
    Notes: Methyl 4-phenylthiophenyl sulfoxide is polymerized to poly(methyl-4-phenylthiophenylsulfonium) in poly(phosphoric acid) with a yield higher than 90%. The demethylation of poly(sufonium cation) is examined to control the composition ratio of the thiophenylene unit in the polycation. The polycation is soluble in common solvents due to the alternative structure of phenylene sufide and phenylenesulfonium cation and is easily converted to poly(phenylene sulfide) through the demethylation with a nucleophile. The poly(sulfonium cation) can be applicable as an alkylating agent for phenol, aniline and benzoic acid to the corresponding to anisole, N-methyl aniline, N,N-dimethyl aniline and benzoic methyl ester, respectively, with high conversion through the demethylation. These products can be isolated without a complicated purification because poly(phenylene sulfide) is precipitated in the mixture as the side product due to the poor solvent solubility.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1994.220050907
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  • 4
    Electronic Resource
    Electronic Resource
    Effect of substituent groups of diphenyl disulfide on novel cationic oxidative polymerization: examination of the electrophilic reaction of the cation by computational calculation (1991)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 2 (1991), S. 149-154 
    Details
    ISSN: 1042-7147
    Keywords: Cationic oxidative polymerization ; Diphenyl disulfide ; AM1 ; π-Frontier electron density ; Poly(phenylene sulfide)s ; 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
    Notes: Substituent groups of the diphenyl disulfides (DPSs) influence the cationic oxidative polymerization in the formation of polyphenylene sulfides (PPSs). A semiempirical MO calculation (AM1) was performed on the model compounds of PPS, such as thioanisoles (TAs) and diphenyl sulfides (PSs), in order to elucidate the reactivity of the cation. Linear PPS is formed on polymerization because of the high electron density of the carbon in the para position. The ratios of the frontier electron density of the carbon in the para position on the disulfide to the sulfur atom are ordered as follows; 3,5-dimethyl-PS〉2,5-dimethyl-PS-3-methyl-PS〉nonsubstituted PS〉2-methyl-PS〉2,6-dimethyl-PS. The formation energies of the σ-complex, which is the intermediate of the reaction, also shows the same order. The theoretical calculation indicates that 3,5-dimethyl disubstituted disulfide and 3-methyl one are most preferable monomers of this cationic oxidative polymerization.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1991.220020306
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