摘要:

AbstractOptically active alkyl‐α‐olefins such as (R)‐3,7‐dimethyl‐1‐octene (1), (S)‐4‐methyl‐1‐hexene (2), and (S)‐5‐methyl‐1‐heptene (3) were copolymerized with styrene (4), 1‐vinylnaphthalene (5) or 2‐methylstyrene (6) by Ziegler‐Natta catalysts based on VCl4, TiCl4or TiCl3“ARA” and Al[CH2CH(CH3)2]3or Al(C2H5)3.Fractionation by solvent extraction as well as optical rotation and differential dichroic absorption (Δε) demonstrate unequivocally the formation of copolymer macromolecules. The isotactic enchainment of the units is supported by IR and X‐ray spectra.A remarkable contribution to optical rotation by aromatic units is observed in the copolymers of 1. In addition circular dichroism data relative to the lowest energy π→π*electronic transition of aromatic nuclei show that aromatic units, when inserted in optically active copolymer macromolecu

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760301

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractMit Hilfe der Wittig‐Reaktion des 2,7‐Fluorendicarbaldehyds (1) mit „Mono‐ und Bis‐Wittig‐Salzen”︁ der Benzol‐ und Thiophenreihe wurden einige Poly(2,7‐fluorenylenvinylenarylenvinylen)e (3a–c) sowie einige dazugehörige Oligomere hergestellt. Die Wittig‐Reaktion des 2‐Fluorencarbaldehyds (6) mit „Mono‐ und Bis‐Wittig‐Salzen”︁ ergab eine weitere Reihe von Oligomeren. Die Struktur der erhaltenen Verbindungen wurde durch Elementaranalyse, IR‐ und Elektronenspektren – die der Oligomeren zusätzlich durch Massenspektren – bestätigt. Ferner wurde die elektrische Leitfähigkeit aller Polymerer und Oligomerer sowie der thermooxidative Abbau

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760302

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractTo characterize the intermediate radicals produced in the initiation of vinyl polymerization with binary systems of diacyl peroxides and tertiary amines, spin trapping technique was applied by using 2‐methyl‐2‐nitrosopropane (8) as a spin trapping reagent. In the reactions ofN,N‐dimethylaniline (2a) andN‐N‐diethylaniline (2b) with benzoyl peroxide (1a),N‐methylanilinomethyl (7) andN‐ethylanilino‐1‐ethyl radicals (16), respectively, were trapped, contrary to benzoyloxyl (4a) and phenyl radicals which were not trapped. This was explained by assuming that benzoyloxyl radicals (4a) react faster with2aor2bto give the radicals7and16, than being trapped with8. From this,4aand7or16were concluded to be the initiating radicals in these systems. In the reaction of lauroyl peroxide (1b) with2aor2b, however, undecyl radicals were trapped together with the radicals7or16. In the case ofN‐ethyl‐N‐methylaniline (2c) both,N‐ethylanilinomethyl (18) andN‐methylanilino‐1‐ethyl radicals (20), were trapped. Further, it was found that in the reaction of1awith poly(p‐dimethylaminostyrene), both poly{1‐[4‐(N‐methyl‐N‐methylylamino)phenyl]ethylene} (22) and phenyl radicals were

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760303

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe reaction of pyromellitic dianhydride (1) with 2,4‐tolylene diisocyanate (2) was investigated. It was found thatN,N′‐bis(isocyanatotolyl)pyromellitimide (3) is formed, which contained three stereoisomers.Polyurethanes containing imide groups in the main chain were synthesized by a polyaddition reaction of the diimide3with α,ω‐diols. The polymers obtained were yellow or yellow brown powders with inherent viscosities (in DMF) of 14–28 cm3/g. DMF, DMSO andm‐cresol were found to be good solvents for these polymers. The results of TG of these polymers w

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760304

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe rate of the thermal decomposition of 2‐tetrazenes (1–5) was measured in the pure state. The activation parameters were calculated from the dependence of the rate constants on the temperature. In order to elucidate the effects of 2‐tetrazenes on the radical polymerization, a kinetic investigation of the polymerization of styrene initiated by 2,2′‐azoisobutylonitrile in the presence of 2‐tetrazene derivatives was also

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760305

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

Abstract6‐Acryloylamino‐2,3‐diphenylchinoxalin (5a) und 6‐Methacryloylamino‐2,3‐diphenylchinoxalin (5b) werden durch Umsetzung von 6‐Amino‐2,3‐diphenylchinoxalin (3) mit den entsprechenden Säurechloriden dargestellt. Die radikalische Polymerisation von5ain Dioxan bei 60°C liefert Polymere mit Erweichungstemperaturen von 270–280°C. Die Polymerisationsgrade sind relativ niedrig.Das Monomere5awird mit Methylmethacrylat radikalisch copolymerisiert. Die Copolymerisationsparameter betragen unter den oben genannten Polymerisationsbedingungen für5ar1= 3,09, für Methylmethacrylatr2=0,89. Die dargestellten Monomeren und Polymeren werden durch IR‐, NMR‐ und

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760306

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractUnvernetzte Copolymere aus Vinylacetat undN‐Vinylpyrrolidon wurden verseift und die erhaltenen Copolymeren als Träger für eine Oligonucleotid‐Synthese in homogener Phase eingesetzt. Desoxythymidin als Kettenanfang wurde über eine Carbonyloxy‐Brücke an den Träger angeknüpft. Die Kettenverlängerung erfolgte zunächst durch Oligokondensation mit ungeschütztem Desoxythymidinphosphat, sodann durch Anbau einer geschützten Nucleotideinheit an das 3′‐Ende. Oligonucleotide des Typs dT (pdT)nund dT (pdT)n– rU wurden auf

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760307

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe polymerization of methyl methacrylate (MMA) was studied in the presence of poly(α‐amino acid)s, water, and copper(II) ion. It was found that the polymerization behaviour depends very much on the conformation of the poly(α‐amino acid) in the system. If the poly(α‐amino acid) had the α‐helix conformation, the polymerization of MMA did not occur. This is supposed to be due to the stability of the intramolecular hydrogen bond in the α‐helix, which is too high to form a chelate complex between the copper ion and the polypeptide together with the MMA monomer and water. When the same polypeptides took a random coil conformation, however, the polymerization occurred, although to a small extent. Furthermore, when the polypeptide with the β‐conformation was used, the polymerization of MMA occured to a higher extent than in the case of the polypeptide with the random coil conformation. Therefore, it was concluded that the delocalization of electrons in the copper ion to the neighbouring atoms plays an important rǒle in the initiation of the polymerization of MMA.It was also found that the size of the nonpolar side chain of the initiating polypeptides affects the polymerization of MMA. Since this polymerization is carried out in water, the hydrophobic bonds between the nonpolar side chain of the polypeptide and the MMA monomer may also play

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760308

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractThe polymerization of vinyl monomers withN‐chlorosuccinimide (1) in the presence of protic acids such asp‐toluenesulfonic acid (PTS) was investigated. From the kinetic studies of the reaction of1with PTS and the polymerization of methyl methacrylate (MMA) with the above combined initiator system, it was found that the polymerization is initiated by a radical produced by a bimolecular reaction between1and PTS, and is terminated by a second order reaction. ESR investigations on the reaction mixture of1with PTS by spin trapping technique clearly showed that the initiating radical is theN‐succinimidyl radical. This radical results from a homolysis of the NCl bond of the protonatedN‐chlorosuc

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760309

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY

摘要:

AbstractDurch Hydrolyse von Copolymeren aus Vinylacetat und 1,4‐Bis(vinyloxy)butan werden vernetzte Polyvinylalkoholgele hergestellt und ihre Eignung als hydrophile stationäre Phase bei gelchromatographischen Trennungen mit Dextranen, Poly(äthylenoxid)en und Proteinen als Testsubstanzen geprüft. Die Gele sind druck‐ und biostabil und zeigen keine störende Adsorption. Je nach Herstellungsbedingungen werden Ausschlußmolekulargewichte bis zu 10

ISSN:0025-116X    

DOI:10.1002/macp.1975.021760310

出版商:Hüthig&Wepf Verlag    

年代:1975

数据来源: WILEY