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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 28 (1983), S. 3671-3679 
    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 novel reactive antioxidants based on tetrazoles that are stable at room temperature and convertible into the highly reactive nitrileimines by pyrolysis were prepared and the reactivity for carbon-carbon double bonds was evaluated. Antioxidants, i.e., 2-substituted phenyl-5-(3′,5′-di-tert-butyl-4′-hydroxyphenyl)tetrazoles (PHPT) were prepared with the reaction of p-toluenesulfonylhydrazone of 3,5-di-tert-butyl-4-hydroxybenzaldehyde and substituted phenyl diazonium chloride in a mixed solvent of pyridine, ethanol, and water at -10°C to -20°C in 31-61% yields. To evaluate the reactivities of PHPT for carbon-carbon double bonds, m-chloro-substituted PHPT was pyrolyzed in an excess of styrene at 160-170°C for 0.5 h to give the 1-(3′-chlorophenyl)-3-(3″,5″-di-tert-butyl-4″-hydroxyphenyl)-5-phenyl-2-pyridazoline in a 44.1% yield by 1,3-dipolar addition reaction of the nitrileimine formed from the m-chloro-substituted PHPT. The thermogravimetric analysis of a mixture of proton isomer of PHPT and liquid polybutadiene showed that PHPT attached to liquid polybutadiene with an accompanying evolution of nitrogen.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 89-98 
    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 chemical reactivities of novel reactive antioxidants based on tetrazoles for carbon-carbon double bonds of liquid polybutadiene and their antioxidation activities toward isoprene rubber were evaluated. These antioxidants, i.e., 2-substituted phenyl-5-(3′,5′ -di-tert-butyl-4′-hydroxyphenyl)tetrazoles (PHPT), were pyrolyzed in liquid polybutadiene at 160-170°C for 30 min to attach to rubber in extents of 61-85% of the nitrileimines formed from PHPT by 1,3-dipolar addition reaction. The reactivities of PHPT followed the order p-Cl 〉 m-Cl 〉 H 〉 p-CH3 〉 m-CH3, p-OC2H5, suggesting that PHPT reacts with diene rubber in electrophilic reaction and p-derivatives exhibit higher contents of binding than m-derivatives due to steric hindrance. From oxygen absorption data, the antioxidation activities of PHPT for isoprene rubber vulcanizates followed the order m-Cl, m-CH3 〉 H, p-Cl, p-Cl, p-CH3 〉 p-OC2H5. Isoprene rubber vulcanizates, obtained after pretreatment with PHPT by heating, were extracted with acetone, followed by aging to show that there was good retention and appreciable antioxidation activities of PHPT, especially, p-CH3 and p-Cl substituted PHPT.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 4201-4201 
    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
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 1197-1202 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monodisperse microspheres of poly(diethylene glycol dimethacrylate) with diameters in the size range 0.4-4.8 μm were prepared by the radiation-induced polymerization. Effects of solvent viscosity and monomer solubility were investigated for various kinds of solvents. The number of the nuclei, produced in the early stage of the polymerization, was found to be constant during the remainder of the polymerization. The nuclei grow to be monodisperse polymer particles without aggregation. This is attributed to the low mobility of the growing polymer particles.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 61 (1996), S. 351-358 
    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 amine functionalization of an acrylamide copolymer was achieved via Hofmann degradation. The starting material, poly(acrylamide-co-methyl methacrylate), was synthesized by radical precipitation polymerization. Using this copolymer, Hofmann degradation at 0°C in a water-dioxane mixture was done using sodium hypochlorite and NaOH. The resulting hydrogel could be dissolved in water-tetrahydrofuran mixtures, and the cast film had a water content of 73%. It was found that the conversion to primary amine was lower, and the extent of a side reaction was higher, compared to those of an acrylamide homopolymer. This was presumed to be due to the lack of the neighboring group effect among acrylamide units since it was a random copolymer. Further modification of this polymer by reacting the amine group is considered to obtain the desired properties for biomedical applications. © 1996 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 13 (1985), S. 191-202 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Recently there has been a growth of interest in the use of diaryliodonium salts (Ar2I+X-), triarylsulfonium salts (Ar3S+X-) and triarylselenonium salts (Ar3Se+X-) as photochemical initiator for cationic polymerizations. It is suggested by Ledwith that electron transfer to these cations results in fragmentation with the formation of aryl radicals and if the reducing species is a suitable free radical, a chain reaction for formation of cation will occur.We carried out radiation-induced polymerization of α-methyl-styrene in dichloromethane and bulk cyclohexene oxide in the presence of triphenyliodonium salt (C6H5)2 (I+PF-). Polymerization of these monomers was observed in the presence of these salts (G(-M)⋍ 1300), while no polymer was obtained in the absence of salts. Postpolymerization was negligibly small. This polymerization is considered to be initiated by the reaction of free radicals produced by radiation with cation salts and to proceed by cationic mechanism, since α-methylstyrene polymerized by ionic mechanism but hardly polymerizes by radical mechanism and this polymerization was suppressed in the presence of a small amount of water. The initiation mechanism of this polymerization was investigated by the use of pulse radiolysis technique.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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