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Uehara, Miyoshi

doi:10.1246/nikkashi1948.86.901

Cited by 6 publications

(4 citation statements)

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“…Chelates react with equimolar amount of phen, as described later, b u t in order t o magnify the effect of additives, excess amounts of them I n a previous paperz), the author has shown that the effectiveness of ketone on the polymerization of styrene by Mn(acac)s increased with the increase in the basicity. UEHARA et al 1) have described that the increasing order of effectiveness on the polymerization of styrene by Mn(acac)s was 2.6-lutidine < pyridine < piperidine. The order is consistent with the ability of coordination to metal, which can be anticipated from basicity and steric hindrancel).…”

Section: Methodsmentioning

confidence: 99%

Polymerization of styrene by metal acetylacetonate/phenanthroline system

Kaeriyama¹

1971

Makromol. Chem.

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Phenanthroline accelerates the polymerization of styrene by P-diketonate chelates of Mn(II), Mn(III), Fe(III), Cu(II), and Co(III), but has no appreciable effect on Ni(I1). Phenanthroline retards the polymerization by acetylacetonate chelate of Co(I1). The initiating radical is generated by a ligand exchange reaction of Mn tris-acetylacetonate with o-phenanthroline. The rate of polymerization is represented as R, cc [styrene]{ [Mn(acac)s] [phenanthroline]}l/2The activation energy and frequency factor are 15.9 kcal/mole and 1.1.106 mole/l.sec in the presence of o-phenanthroline. The values are compared with those without additives and in the presence of pyridine. Initiation mechanisms are proposed. ZUSAMMENFASSUNG: Die Polymerisation von Styrol in Gegenwart der P-Diketonchelate von Mn(II), Mn(III), Fe(III), Cu(I1) und Co(II1) wird durch Phenanthrolin beschleunigt ; hingegen ubt dieses in Gegenwart des Ni(I1)-chelates keine nennenswerte Wirkung auf die Polymerisation aua. Bei der Polymerisation durch das Acetylacetonat-Chelat des Co(I1) ubt Phenanthrolin sogar eine verzogernde Wirkung aus. Das initiierende Radikal bildet sich durch Austausch eines Liganden des Mangantriacetylacetonats gegen o-Phenanthrolin. Die Polymerisationsgeschwindigkeit wird wiedergegeben durch R, cc [Styroll{ [Mn(acac)s] [Phenanthrolin]}l/Z Die Aktivierungsenergie und der Frequenzfaktor in Gegenwart von o-Phenanthrolin betragen 15,9 kcal/Mol und 1,1.10~Mol~Z-~~sec-~. Diese Werte werden mit den ohne Zusatzstoffe und mit den in Gegenwart von Pyridin erhaltenen Werten verglichen. Es werden Initiierungsmechanismen vorgeschlagen.

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Section: Methodsmentioning

confidence: 99%

Polymerization of styrene by metal acetylacetonate/phenanthroline system

Kaeriyama¹

1971

Makromol. Chem.

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“…6, the third-term of Eq. , (10) is negligible and the intersection of the curve with the ordinate .gives C b1=6.2x10-s • The plot of (1/Pn-C1l 1)/ R l1 vs R, as is shown in Table 2 shows the results of polymeriza tion of MMA in the presence of various aromatic amines, The effect of pyridine was also investigated for the purpose of comparison which was known to have strong coordination power with metal chelates, As is seen from Table 2, the aromatic. amines markedly increased the rate of polyrnerizatlon initiated by Ni (eacacj, while pyridine had no such accelerating effect.…”

Section: Chain Transfermentioning

confidence: 99%

Studies on Polymerization of Vinyl Compounds Initiated by Metal Chelate II Kinetics of Polymerization of Methyl Methacrylate Initiated by Nickel Ethyl Acetoacetate in the Presence and the Absence of Aromatic Amines

Chen

Lin

Huang

et al. 1970

J Chinese Chemical Soc

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The kintetic studies of polymerization of methyl methacrylate initiated with nickel ethyl acetoacetate gave the following . Some aromatic amines such as aniline markedly accelerated the polymerization, while pyridine had no such effe:::t. The activation energy of initiation was 24.8 kcalfmot in the absence of aniline, and 8.8 kcal/mol in the presence of aniline. Both the kinetic data and the infrared spectra of the polymer indicated that the polymerization was radical in nature. The reaction order against monomer varied, as the temperature differed. The spectrophotometric investigation indicated formation of a complex between the chelate and the monomer, or amines. It also showed that the formation of a complex was not a factor which controlled the rate of initiation. A scheme of initiation mechanism was .presented on the basis of the above experimental evidence. InboducHonPolymerization of vinyl compounds initiated by metal chelates of l3-diketones has been studied by a few wcrker.P"? TJ1e function of the chelates has been considered a ttribu ta ble to the formation 145

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“…Polarographic data for the semicarbazones and thiosemicarbazones of 2-, 3-, and 4-pyridinecarboxyaldehydes, 2-, 3-, and 4-acetylpyridine, and their Ar-oxides were reported (1055). The effect of structure was considered in the reduction study of a series of azomethines (1348). Reduction of the aldoxime of phenylglvoxal and 2-furylglyoxal, 2acetylfuranoxime, and phenylglyoxalphenvlhydrazone was studied as a function of pH (1285).…”

Section: Amperometric Titration Proceduresmentioning

confidence: 99%