摘要:

AbstractIn order to elucidate the initiation mechanism of the vinyl polymerization by amine‐copper(II) complexes in aqueous solution, in the presence of carbon tetrachloride, the reaction of amine‐copper(II) complexes with carbon tetrachloride was studied by ESR, visible spectroscopy, and the spin trapping method. The ESR signal of copper(II) disappeared during the reaction, suggesting the reduction of copper(II) to copper(I) in the initial step of the reaction. This reduction was also ascertained both by visible spectral changes and by the cuproin coloration method. The initiation mechanism is discussed based on these results and the information about the initiating free radical species by the spin trapping met

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761101

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractOn a synthétisé à l'aide de la technique de polymérisation par voie anionique des copolymères séquencés poly(méthacrylate d'alkyle)/poly(oxyéthylène). On a opéré sous vide, en milieu tétrahydrofuranne; l'initiateur utilisé était le diphénylméthylpotassium.Dans le cas des copolymères poly(méthacrylate d'éthyle)/poly(oxyéthylène), les échantillons ont été fractionnés par addition progressive de triméthyl‐2,2,4 pentane à leur solution dans le benzène. On a caractérisé les différentes fractions par résonance magnétique nucléaire diffusion de la lumière. On a montré que les copolymères bruts ainsi préparés ne renfermaient pas d'homopolymère et que les fractions recueillies présentaient une faible polydisper

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761102

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractOligoesters having a 9‐carbazolyl group attached to the main chain were prepared by oligocondensation of 9‐[1,1‐bis(hydroxymethyl)ethyl]carbazole (2a) with diethyl malonate, dimethyl terephthalate, and diethyl 2‐(carbazol‐9‐yl)‐2‐methylmalonate (1). Charge transfer complex formation of these oligoesters and their monomeric model compound with 2,4,7‐trinitrofluorenone was investigated by means of absorption spectroscopy. The stability constants (K) of the oligomeric systems were always larger than those of the monomeric systems. The magnitude ofKwas found to be in the following order:oligo[oxy‐(2‐carbazol‐9‐yl‐2‐methyl)trimethyleneoxy‐(2‐carbazol‐9‐yl‐2‐methyl)‐malonyl] (3c) ≫ oligo[oxy‐(2‐carbazol‐9‐yl‐2‐methyl)trimethyleneoxymalonyl] (3a) ≈ oligo[oxy‐(2‐carbazol‐9‐yl‐2‐methyl)trimethyleneoxyterephthaloyl] (3b)>9‐[1,1‐bis‐(acetoxymethyl)ethyl]carbazole (2b).Fluorescence spectroscopy of these carbazolyl derivat

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761103

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractBased on the reaction between acid chlorides and amines, two techniques were developed to prepare graft and block copolymers. In the first method poly(methyl methacrylate), (PMMA), containing chloroformyl groups was reacted with 2,2′‐azodiisobutyramidine (1) or 2,2′‐azobis[2‐(2‐imidazolin‐2‐yl)propane] (2) to give a polymeric initiator which, on thermal activation in the presence of acrylamide, produced graft and block copolymers, according to the position of the chloroformyl group on the PMMA backbone. In the second method, PMMA containing one terminal chloroformyl group was directly reacted with polyacrylonitrile containing two terminal amidine groups to produce a

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761104

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractEs wurden einige Übergangsmetallchelate2a–e, 4a,bund6a,bmonomerer und polymerer Schiffscher Basen (1, 3und5) aus Salicylaldehyd und 2‐Aminophenol, bzw. 2,4‐Diamino‐5‐hydroxyphenol, sowie aus 2,5‐Dihydroxyterephthalaldehyd und (2,4‐Diamino‐5‐hydroxyphenol) dargestellt und ihre katalytischen Eigenschaften für die Autoxidation von Cumol untersucht. Die Aktivität nimmt in der Reihenfolge Mn>Co>NI>Cu>Zn sowie mit steigendem Molekulargewicht der Schiffschen Base ab. Die Verbindungen katalysieren auch die Zersetzung von Cumolhydroperoxid; am wirksamsten erwiesen sich auch hi

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761105

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractSome copolymers ofL‐glutamic acid andL‐tyrosine are treated withp‐carboxybenzenediazonium chloride. Monoazotyrosine chromophores can be obtained along the polypeptide chains in the presence of a stoichiometric quantity of the reagent, whereas an excess of the reagent gives rise to the formation of a mixture of mono‐ and bis‐azoderivatives. In all the cases only a part of the total number of the tyrosine residues can be modified. The results are discussed on the basis of the pKavalues for the ionization of tyrosine and azo‐tyrosin

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761106

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

Abstract1,1,4,4‐Tetraphenyl‐2‐tetrazene (1) inhibits the radical polymerization of styrene initiated by 2,2′‐azoisobutyronitrile. The inhibition period is proportional to the concentration of1. The rate of the initiation of polymerization and the ratio of the rate constants of propagation and termination reactionsk 2p/2kt, were calculated from the consumption rate of the inhibitor. Some aromatic amines did not effect the inhibition period and the polymerization rate. Tetraphenylhydrazine showed a retar

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761107

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe red‐violet complex which was formed from partially saponified poly(vinyl acetate) and iodine in the presence of potassium iodide was investigated by theBenesi‐Hildebrandmethod. The molar absorption coefficient of the complex at the absorption maximum (488 nm) was found to be 4,74.1041/(mol cm) at 10°C and to decrease with rising temperature. The concentration of units resulting from vinyl acetate (acetoxyethylene units), which can take part in the complex formation with iodine, was below 1% of the total content of acetoxyethylene units in the polymer. The changes of enthalpy (ΔH) and entropy (ΔS) were found to be −45,01 kJ mol−1(−10,75 Kcal/mol) and −48,40 J mol−1K−1(−11.56 cal mol−1K−

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761108

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractPhotocrosslinkable polymers containing chalconecarbonyl units were prepared. 2‐Methacryloyloxyethyl 4‐chalconecarboxylate (1) and 2‐methacryloyloxyethyl 4′chalconecarboxylate (2) were synthesized and polymerized by a radical initiator.1was copolymerized with methyl methacrylate. The properties of the resulting polymers as photosensitive resins are de

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761109

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractTheS‐dodecyl (1e),S‐decyl (1d), andS‐octyl esters of thio‐β‐alanine (1c) were condensed in the presence of a base in aqueous media to give poly(β‐alanine) in yields of 44, 24, und 2%, respectively. The degrees of polycondensation of the obtained poly(β‐alanine) were 13, 12, and 20, respectively.S‐hexyl ester (1b) andS‐ethyl ester (1a) gave no polymer. The process of this polycondensation reaction was explained by a proposed matrix reaction on

ISSN:0025-116X    

DOI:10.1002/macp.1975.021761110

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY