摘要:

AbstractThe polymerizations of acrylonitrile, methyl methacrylate and styrene initiated by copper(II) chelates were studied in the presence of carbon tetrachloride. Polymeric and dimeric compounds of vinyl alcohol, that is poly(vinyl alcohol) and 1,3‐propanediol were chosen as ligands. It was found that these systems could initiate the polymerization of methyl methacrylate and styrene effectively. The activity of the polymer chelate was estimated by varying the metal/ligand mole ratio of the initiator system, the pH values and the polymerization temperature. From the results, the mechanism of the free‐radical formation was discus

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750111

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractThe hydrochloride of phenylalanineS‐dodecyl ester (2b) reacts in pyridine/water at room temperature to afford 3,6‐dibenzyl‐2,5‐piperazinedione (3) in good yields. PhenylalanineS‐ethyl ester hydrochloride (2a), however, gives only small yields of3under the same conditions. This effect is explained with the assumption of a matrix reaction on the micelle surface. In contrast to theS‐ethyl ester the reaction of theS‐dodecyl ester leads to a mixture of two isomeric dio

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750112

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractIn order to elucidate the initiation mechanism of the polymerization of acrylamide by ceric salt, the complexation of ceric salt with acrylamide and its methylated derivatives was investigated by IR and NMR spectrometry. The decomposition of the complex was also studied by determining the rate of ceric salt consumption. From the results it was concluded that the oxygen of acrylamide coordinates with the ceric ion to form the complex and that a radical is produced by abstraction of a hydrogen atom from the amide group of the molecule to initiate the polymerization.

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750113

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractCopolymerizations of 4(5)‐vinylimidazole (1) and γ‐vinyl‐γ‐butyrolactone (2) initiated by 2,2′‐azoisobutyronitrile or benzoyl peroxide were carried out. The initiators did not affect the radical reactivity ratio (r). In addition, the reactivity ratio was not influenced by methanol as solvent. The following ratios were obtainedr1= 20,0 ± 0,8 andr2= 0,030 ± 0,002.The catalytic activity of the copolymers in the hydrolyses ofp‐nitrophenyl acetate (4) and 3‐acetoxy‐N,N,N‐trimethylanilinium iodide (5) at pH = 8,0 was found to be more than twice as high as that of a random terpolymer containing imidazole, carboxylic aci

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750114

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractPolyketones with carbonyl groups in the polymer backbone (ethylene‐carbon monoxide copolymer) have been converted into a novel polyoxime by means of C‐nitrosation of the methylene groups and oximation of the carbonyl groups. The polyoxime is considered to be composed largely of 1,2‐bis(hydroxyimino)trimethylene units. From the polyoxime and divalent Fe‐, Co‐, or Ni‐salts, polymeric metal chelate complexes were prepared which are capable of combining reversibly with molecular oxygen and, especially the Fe‐complex, also with ca

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750115

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractAromatic aliphatic copolyimides (19a–m) containing pyromellitdiimide and glutar‐ or succinimide rings in the main chain were synthesized by a two‐step reaction of specified dianhydrides (5a, b) with primary diamines (11a–h). In the first step, poly(amic acid)s (17/18) having pyromellitdiimide rings were prepared by the reaction of 2,2′‐pyromellitdiimido‐diglutaric or disuccinic anhydride (5b, 5a) with11a–hin polar solvents. In the second step, the conversion of17/18to the copolyimides19a–mwas carried out either thermally or by chemical means.5band5awere synthesized by the reaction of pyromellitic anhydride with glutamic or aspartic acid, respectively. No gelation was observed during a long period of storage of the poly(imidoamic acid)s17/18in polar solvents at room temperature. For their conversion to copolyimides, a dehydrating agent such as acetic anhydride and a catalyst such as pyridine were applied successfully. The copolyimides gave clear, tough and flexible films from DMSO solution. They show excellent stabilities at high temperatures and against oxidative degradation. IR spectra, solubilities, TG analyses and the formation of the new copolyimides were studied and compared with those of correspondin

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750116

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractReductions ofcis‐[Co(en)2PVPCl]2+(1) [PVP = poly(4‐vinylpyridine)] by ferrous aquoions and ferrous chelate ions were studied. The rate of reduction by Fe2+is small compared to that of the monomeric analogue,cis‐chlorobis(ethylenediamine)pyridine cobalt(2+) (cis‐[Co(en)2PyCl]2+) due to the electrostatic repulsion. On the other hand, the reduction by [Fe‐(edta)]2−is accelerated by a factor of 20. With increasing degree of coordination the acceleration factor increases, and with increasing ionic strength the factor decreases. The acceleration was found to be due to the electrostatic attraction of the reductant by the polymer as a polycation. The electrostatic effect is discussed in comparison with the catalysis of polyelectrolytes in ioni

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750117

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractCobalt(III)‐complexes having a polymeric ligand,cis‐[Co(en)2PVPCl]Cl2,cis‐[Co(trien)‐PVPCl]Cl2,cis‐[Co(en)2PVPBr]Br2,cis‐[Co(en)2PVPN3]Cl2andcis‐[Co(en)2QPVPCl]Cl2(where PVP = poly(4‐vinylpyridine) and QPVP = partially quarternized PVP) were prepared and their reduction with ferrous sulfate was studied. Complex formation with QPVP was shown to be affected by steric factors such as the degree of polymerization and the bulkiness of the quaternizing agents, but the quarternization showed only a small steric influence on the reduction kinetics. The order of the reduction rate ofcis‐[Co(en)2PVPX]2+with respect to the bridging ligand X is N3>Cl>Br, and the reduction rate ofcis‐[Co(en)2PVPCl]2+is higher than that ofcis‐[Co(trien)PVPCl]2+. The effects of bridging and non‐bridging ligands in the reduction of polymer complexes were the same as those for

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750118

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractBy use of rotating sector technique at high pressure, the average life times of the growing polymer radical in the bulk polymerization of methyl methacrylate was measured over the pressure range of 1—1000 kg/cm2at 250 kg/cm2pressure interval. The rates of initiation at the same pressure interval was also determined by the measurement of consumption of the inhibitor usingN′,N′‐diphenyl‐N‐picrylhydrazyl as radical scavenger. The effect of pressure on the individual rate constants for the methyl methacrylate polymerization was evaluated from both experimental results and the activation volumes of the propagation and the termination was obtained as −19,0 and 25,0 cm3/mol, respectively. Their values have been compared with those of styrene p

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750119

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY

摘要:

AbstractA study on thin layer chromatographic (TLC) separation of polybutadienes with three different microstructures, namely,trans‐1,4,cis‐1,4, and 1,2‐vinyl, was carried out. An experimental procedure to separate three possible binary mixtures of these polymers into each component species is established in an alternate use of carbon tetrachloride and amyl chloride as developer. Further it is shown that this procedure combined with a two‐dimensional TLC development technique allows to separate the ternary polymer mixture into components. In addition, the chromatographic behavior of so‐called “equibinary” polybutadienes has been investigated using the technique estab

ISSN:0025-116X    

DOI:10.1002/macp.1974.021750120

出版商:Hüthig&Wepf Verlag    

年代:1974

数据来源: WILEY