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  • 1
    Electronic Resource
    Electronic Resource
    Application of spin trapping technique to radical polymerization, 15.Part 14: cf.7. Photo-decomposition of dibenzoyl disulfide and evaluation of relative reactivities of vinyl monomers toward the benzoylthiyl radical (1977)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 178 (1977), S. 1951-1958 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mechanism of photo-decomposition of dibenzoyl disulfide (DBDS) in benzene or in monomers, and the evaluation of relative reactivities of various vinyl monomers toward the benzoylthiyl radical (4) were investigated by means of the spin trapping technique using 2-methyl-2-nitrosopropane (BNO). When DBDS photo-decomposed in benzene at 22±2°C in the presence of BNO, both 4 and benzoyl radicals were trapped as their nitroxyl radicals, indicating that both S—S and C—S bonds in DBDS were decomposed during its photolysis. However, when the photo-decompositions were performed in the monomers, propagating radicals (7) were trapped, but no allyl-type radicals (11). The coupling constants of the nitroxyl radicals of various propagating radicals were determined. From the ESR spectra of the systems DBDS/vinyl monomers/methyl methacrylate (as reference)/BNO the relative concentrations of the nitroxyls, [8]/[10, X = COOCH3], were determined by computer simulation, and the relative reactivities of the vinyl monomers toward 4 were estimated. It was found that the relative reactivities of these monomers are correlated with their e values to give a linear relationship with a negative slope, similar to those toward the tert-butoxyl radical found in the previous paper.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1977.021780709
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  • 2
    Electronic Resource
    Electronic Resource
    Application of spin trapping technique to radical polymerization, 13Part 12: Makromol. Chem. 178, 1259 (1977), preceding paper. Polymerization of methyl methacrylate with 1,2,3,10a-tetrahydrophenanthrene-1,2-dicarboxylic anhydride (1977)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 178 (1977), S. 1267-1276 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The polymerization of methyl methacrylate (MMA) with 1,2,3,10a-tetrahydrophenanthrene-1,2-dicarboxylic anhydride (TH) (10), which is a stable Diels-Alder adduct of α-vinylnaphthalene and maleic anhydride, was investigated by kinetic and spin trapping methods. TH could induce radical polymerizations of MMA and methyl acrylate with a considerably high rate, and the rate of polymerization (Rp) of MMA was found to follow the equation: Rp = k[TH]0,3 [MMA]1,6. The overall activation energy and the chain transfer constant to TH for this polymerization were determined to be 47,7 kJ/mol and 0,52, respectively. From these results, an initiation mechanism involving a hydrogen-transfer from TH to MMA was proposed, which is similar to Mayo's initiation mechanism for the thermal polymerization of styrene. To confirm this mechanism, the spin trapping technique was applied. The results obtained regarding the trapping of the initiating radicals supported this hydrogen-transfer initiation mechanism.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1977.021780505
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  • 3
    Electronic Resource
    Electronic Resource
    A study on long-lived propagating polymer radicals of acrylamide derivatives at room temperature (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 267-269 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021800128
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  • 4
    Electronic Resource
    Electronic Resource
    Oxidation of tertiary amines with N-chloronylon 66 (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 299-305 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Oxidation of tertiary amines with N-chloronylon 66 (NCN) was investigated in several organic solvents. NCN was found to oxidize N,N-dimethylaniline (DMA) at room temperature to give N-methylaniline with 15-50% yield, depending on the solvents used. Oxidation of N,N-dimethylbenzylamine (DMBA) gave benzaldehyde with 15-30% yield and a small amount of N-methylbenzylamine. A mechanism was discussed. For comparison, N-chlorosuccinimide, a low molecular N-chloro-compound, was also used for oxidation of DMA and DMBA.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021800201
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  • 5
    Electronic Resource
    Electronic Resource
    Application of spin trapping technique to radical polymerization, 16.Part 15: cf.2. Photo-decomposition of diphenyl disulfide and initiation mechanism: Evaluation of relative reactivities of vinyl monomers toward phenylthio radical (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 1165-1174 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: To clarify the initiation process in radical polymerizations with diphenyl disulfide (DPDS) as initiator, spin trapping technique was applied to the reaction of vinyl monomers with the phenylthio radical (1), which was produced by photolysis of DPDS. 2-Methyl-2-nitrosopropane (BNO) was used as a spin trapping agent. When DPDS was photo-decomposed in benzene in the presence of BNO radical 1 was trapped as the corresponding aminyl oxide radical 2, which is unstable at room temperature. The photolysis of DPDS in vinyl monomers of type H2C=CXY, however, gave only aminyl oxide radicals resulting from their propagating radicals C6H5S—CH2—C·XY. Contrary to the results obtained with tert-butoxyl radicals, radical 1 was found to undergo exclusively addition reaction to the double bond of the α-methyl-substituted monomers, such as methyl methacrylate or methacrylonitrile, with no hydrogen-abstraction reaction from their α-methyl group. Relative rates of the initiation reactions of vinyl monomers with radical 1 were also determined by spin trapping technique. It was found that the reactivities of vinyl monomers toward radical 1 are controlled by both polar and resonance effects.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021800505
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  • 6
    Electronic Resource
    Electronic Resource
    Application of spin trapping technique to radical polymerization, 17.Part 16: Makromol. Chem. 180, 1165 (1979).N-hydroxysuccinimide as a radical initiator (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 1175-1182 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: N-hydroxysuccinimide (NHS) and N-hydroxyphthalimide were found to initiate effectively vinyl polymerizations of acrylate monomers. The polymerization of methyl methacrylate (MMA) with NHS was investigated in detail. The polymerization rate (Rp) was found to depend highly on the solvents. The over-all activation energy of the polymerization in ethyl acetate was calculated to be 76,2 kJ/mol (18,2 kcal/mol). In the low monomer concentration, Rp can be expressed as Rp = k [NHS]1/2 [MMA]3/2. The copolymerization of MMA with styrene, initiated by NHS, could be shown to proceed via radical mechanism. In order to elucidate the initiation mechanism, spin trapping technique was applied to this polymerization system. In the reaction of MMA with NHS in acetone, the 2-carbomethoxypropyl radical was trapped by 2-methyl-2-nitrosopropane, a spin trapping reagent, to give the corresponding aminyl oxide radical 2. From the results, the initiation mechanism of this polymerization is proposed and discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021800506
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  • 7
    Electronic Resource
    Electronic Resource
    Long-lived polymer radicals, 2Part 1: cf.1.. An ESR study on the reactions of the propagating polymer radicals of N-methylacrylamide and N-methylmethacrylamide with vinyl monomers at room temperature (1980)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 181 (1980), S. 2421-2431 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Acrylamide (AAm), methacrylamide (MAm), N-methylacrylamide (NMAAm) and N-methylmethacrylamide (NMMAm) were found to yield long-lived propagating polymer radicals in the photo-sensitized polymerizations in 1,4-dioxane or benzene. The concentration of poly(NMAAm) radicals reached 1.10-3 mol/l. Some post-effect was observed at room temperature in the photo-sensitized polymerization of AAm with di-tert-butyl peroxide in 1,4-dioxane, while no post-polymerization proceeded at room temperature in the polymerization of NMMAm in benzene. The reactions of poly(NMAAm) and poly(NMMAm) radicals with various vinyl monomers were found to produce long-lived propagating polymer radicals of the second monomers at room temperature. Polymer radicals of non-homopolymerizable monomers such as α-methylstyrene and 1,1-diphenylethylene were easily formed in such a block-copolymerization matrix. The formation of the propagating polymer radicals of the vinyl monomers was investigated by means of ESR spectroscopy.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1980.021811121
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  • 8
    Electronic Resource
    Electronic Resource
    Application of spin trapping technique to radical polymerization, 18Part 17: Makromol. Chem. 180, 1175 (1979).. Initiation mechanism of vinyl polymerization with N,N-dimethylaniline N-oxide/acid anhydride systems (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 1911-1916 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mechanism of radical formation from the radical initiator systems N,N-dimethylaniline N-oxide (DMAO)/acid anhydride, was investigated by spin trapping technique. 2-Methyl-2-nitrosopropane (BNO) was used as spin trapping reagent. In the DMAO/acetic anhydride system, both methyl and N-methylanilinomethyl radicals were trapped by BNO as the corresponding amine N-oxyl radicals. However, only ethyl and undecyl radicals were trapped from DMAO/propionic anhydride and from DMAO/lauric anhydride system, respectively. In the DMAO/benzoic anhydride system, the amine N-oxyl radical derived from N-methylanilinomethyl radical and another amine N-oxyl radical were observed. The latter one is likely to be derived from a radical formed by hydrogen abstraction from the methyl group of DMAO by a benzoyloxyl radical. When the concentrations of DMAO and benzoic anhydride were lowered, phenyl radical was also trapped. From these findings, the initiation mechanism of vinyl polymerization with the DMAO/acid anhydride systems was proposed and discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021800806
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  • 9
    Electronic Resource
    Electronic Resource
    ESR determination of rate constants for the radical polymerization of methyl phenethyl itaconate (1987)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 188 (1987), S. 2951-2961 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Phenethyl 2-(methoxycarbonylmethyl)acrylate (methyl penethyl itaconate) (1) was prepared and its polymerization with dimethyl 2,2′-azoisobutyrate (2) was investigated kinetically in benzene. The polymerization rate (Rp) was found to be expressed by Rp = k·[2]0,5·[1]1,8 (at 50°C). Further, a higher dependence of Rp (2nd order) on the concentration of 1 was observed at 61°C. The overall activation energy of the polymerization was calculated to be a low value of 50,3 kJ/mol. The initiator efficiency (f) of 2 was determined to be 0,48 to 0,22 at 50°Cand 0,50 to 0,28 at 61°C. f decreases with increasing monomer concentration due to the high viscosity of 1. The poly(1) radical is stable enough to be observable by ESR at high temperatures (50-60°C). Rate constants of propagation (kp) and termination (kt) were estimated using the poly(1) radical concentration determined by ESR. kp [6,0 to 121/(mol·s) at 50°Cand 7,1 to 15 1/(mol·s) at 61°C] shows a trend to increase with the concentration of 1. On the other hand, kt [2,9·104 to 17·1041/(mol·s) at 50°Cand 6,9·104 to 45·1041/(mol. s) at 61°C] decreases with increasing MPI concentration. This behavior is responsible for the high order with respect to monomer concentration. Copolymerization of 1 (M1) with styrene (M2) at 50°Cgave the following results: r1 = 0,36, r2 = 0,40, Q1 = 0,82 and e1 = + 0,59. Using the above results, the rate constants of the cross-propagations were estimated to be k12 = 22 1/(mol·s) and k21 = 308 1/(mol·s) at 50°C.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1987.021881216
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  • 10
    Electronic Resource
    Electronic Resource
    Kinetic and ESR studies of the radical-initiated polymerization of N-(2,6-dimethylphenyl)itaconimide (1991)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 192 (1991), S. 2231-2241 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The polymerization of N-(2,6-dimethylphenyl)itaconimide (1) with azoisobutyronitrile (2) was studied in tetrahydrofuran (THF) kinetically and spectroscopically with the electron spin resonance (ESR) method. The polymerization rate (Rp) at 50°C is given by the equation: Rp = K[2]0,5 · [1]2,1. The overall activation energy of the polymerization was calculated to be 91 kJ/mol. The number-average molecular weight of poly(1) was in the range of 3500-6500. From an ESR study, the polymerization system was found to involve ESR-observable propagating polymer radicals of 1 under the actual polymerization conditions. Using the polymer radical concentration, the rate constants of propagation (kp) and termination (kt) were determined at 50°C. kp (24-27 L · mol-1 · s-1) is almost independent of monomer concentration. On the other hand, kt (3,8 · 104-2,0 · 105 L · mol-1 · s-1) increases with decreasing monomer concentration, which seems mainly responsible for the high dependence of Rp on monomer concentration. Thermogravimetric results showed that thermal degradation of poly(1) occurs rapidly at temperatures higher than 360°C and the residue at 500°C was 12% of the initial polymer. For the copolymerization of 1 (M1) with styrene (M2) at 50°C in THF the following copolymerization parameters were found; r1 = 0,29, r2 = 0,08, Q1 = 2,6, and e1 = +1,1.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1991.021921004
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