摘要:

AbstractPentacyanobenzylcobaltate(III) acts as an effective initiator for the polymerization of methyl methacrylate (MMA), styrene, acrylonitrile, and vinyl acetate, and the initiating radical is assumed to be the benzyl radical produced from homolysis of the Carbon‐cobalt bond. The binary systems of pentacyanocobaltate(II) and some organic halides were also found to serve as initiators for the MMA polymerization. The initiating activity of these systems increased with decreasing dissociation energy of the carbon‐halogen bond in the halides. The polymerization of MMA and styrene by pentacyanobenzylcobaltate(III) was accelerated in the presence of benzyl brom

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260101

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractAn investigation has been made on the polymerization of methyl methacrylate (MMA), with the following initiator systems: 1. binary system of metallic tin and benzyl chloride, 2. binary system of reduced nickel and tin tetrachloride, and 3. benzyltin compounds. All systems were found to initiate the radical polymerization of MMA.The rate of polymerization (Rp) of MMA initiated with tetrabenzyltin in benzene at 80°C may be expressed as follows:\documentclass{article}\pagestyle{empty}\begin{document}$$ \rm R_p = k\left[ {MMA} \right]^{1_ \bullet 3} \left[ {\left( {C_6 H_5 CH_2 } \right)_4 Sn} \right]^{0_ \bullet 5} $$\end{document}The overall activation energy for this polymerization was estimated to be 12.5 kcal/mole. Tetrabenzyltin was also observed to serve as a photosensitizer in the polymerization of MMA.It was also found that the system metallic tin/benzyl chloride induced selectively the cationic polymerization of isobutyl vinyl ether as well as the radical polymerization of MMA

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260102

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractThe polymerization of methyl methacrylate can be easily initiated in systems containing poly‐2‐vinylpyridine (polymer electron donor), liquid sulfur dioxide (acceptor), and carbon tetrachloride. The various types of polymer electron donors and acceptors which range widely in their electron affinity were also examined. The addition of DPPH causes the retardation; a decrease in the poly‐2‐vinylpyridine concentration or an increase in the monomer concentration leads to a higher molecular weight of poly‐MMA. The values of kp/√ktobtained under the various polymerization conditions are satisfactorily consistent with the literature values, suggesting that the polymerization proceeds through free radical in

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260103

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractVinylchlorid und Styrol wurden bei Temperaturen zwischen −78 und 50°C durch60Co‐γ‐Strahlung copolymerisiert. Die Zusammensetzung der Copolymeren wurde in Abhängigkeit von der Temperatur und der Zusammensetzung des Monomergemisches bestimmt. Die formalen Copolymerisationsparameter wurden berechnet, und es wurde versucht, aus den IR‐Spektren der Copolymeren qualitative Aussagen über die Verteilung der Monomereinheiten in den unter verschiedenen Bedingungen hergestellten Copolymeren zu machen. Die Ergebnisse weisen darauf hin, daß die Copolymerisation bei Temperaturen von −78 bis +20°C teilweise nach einem radikalischen, teilweise nach einem ionischen Mecha

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260104

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractPolystyrol, Polyvinylchlorid, Mischungen dieser Polymeren und Styrol/Vinylchlorid‐Copolymere, die unter verschiedenen Bedingungen (s. Teil I) hergestellt worden waren, wurden im Feldionenmassenspektrometer pyrolysiert. Während die Pyrolyse der Polymermischungen praktisch die gleichen Belegungen von Massenzahlen ergibt wie die Feldionenmassenpyrogramme der Homopolymeren, treten in den Copolymeren zusätzlich in großer Menge Fragmente mit Massenzahlen zwischen 100 und 250 auf. Nach der Intensität des Phenylbutadiens (MZ = 130), das sich aus benachbarten Monomereinheiten des Styrols und des Vinylchlorids bildet, wurde der Blockcharakter der einzelnen Polymerproben beurteilt. Die Ergebnisse wurden mit den kinetischen und den IR‐Untersuchungen verglichen. Durch langsame Pyrolyse bei niedrigen Temperaturen (350–400°C) wurde gezeigt, daß der thermische Abbau innerhalb der Vinylchloridsequenzen der Polymerke

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260105

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractPeresters can decompose thermally by several modes. There can be simple scission of the OO bond or a simultaneous scission of both the OO and the CC bond to split out carbon dioxide. The decompositions oftert‐butyl peracetate,tert‐butyl per(phenyl acetate) andtert‐butyl per(diphenyl acetate), have been studied and it has been shown that whereastert‐butyl peracetate decomposes primarily into alkoxy and acyloxy radicals, the other two dissociate into the products with simultaneous splitting of carbon dioxide in a single stage reaction. This suggests that peresters with groups that would form relatively stable radicals undergo a synchronous scission of the two bonds to split out a mo

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260106

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractAlicyclic polyamic acids and their polybenzoxazinones were prepared by the polycondensation oftrans‐ andcis‐1.4‐ and 1.3‐cyclohexane dicarboxylic acid chloride with 4,4′‐diaminobiphenyl‐3.3′‐dicarboxylic acid. Comparing these alicyclic polymers with corresponding fully aromatic polybenzoxazinones, it was demonstrated that the symmetry of the molecules rather than aromaticity is a more important factor for the solubility of polymers. Thetrans‐1.4‐acid chloride is easier polymerizable than thecis‐1.4‐isomer. The polybenzoxazinone from thetrans‐1.4‐isomer shows higher thermal stability than that from thecis‐1.4‐isomer. The reaction variables of the cyclopolycondensation were studied and some of the properties of the

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260107

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractStyrene was polymerized in the presence of polyepichlorohydrin with borontrifluoride etherate as a catalyst. The product was fractionated and it was found that a copolymer of styrene and epichlorohydrin was formed. The activation energy for the incorporation of styrene is 26 kcal/mole which is higher than that usually found in cationic polymerizations. A possible mechanism for the formation of the copolymer is discussed.

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260108

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractPhenylphosphonic diisocyanate has been prepared and polymers from its condensation with diamines using the interfacial technique are reported. The polymers are believed to contain the following repeating structure:

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260109

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY

摘要:

AbstractFür die Darstellung von 4‐Vinyldiphenyl und 11‐Vinyl‐p‐terphenyl wurden einfache, verallgemeinerungsfähige Synthesen ausgearbeitet. Durch Umsetzung entsprechender Carbinole mit Methansulfonsäurechlorid in Pyridin gelang die Darstellung der Vinylverbindungen in einer einstufigen Reaktion.Die Untersuchung der radikalischen Copolymerization der Monomeren mit Styrol ergab bei 4‐Vinyldiphenyl und 12‐Vinyl‐p‐terphenyl einen bevorzugten Einbau in die Polymerketten, während 11‐Vinyl‐p‐terphenyl nur in untergeordnetem Maße in Polyst

ISSN:0025-116X    

DOI:10.1002/macp.1969.021260110

出版商:Hüthig&Wepf Verlag    

年代:1969

数据来源: WILEY