摘要:

AbstractA description is given of number average molecular weight measurement by activity depression of polymer solution at 37°C.The detected temperature difference is elucidate to be time‐dependent, and extrapolated values of temperature difference give correct values.Three thousands of molecular weight for polybutadiene was given by using chloroform with three percents error of 95% confidence lim

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790101

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractEarlier investigations have revealed significant stoichiometric anomalies in the inhibition of radical polymerization. The experimental value of the stoichiometric coefficient was found to be always smaller than the theoretical one and to be independent of the temperature. The factors governing the reactivity of the inhibitor have been stated to have no part in the determination of the value of the stoichiometric coefficient.In the present study an attempt was made to interpret this general phenomenon on the assumption that before having lost the reaction heat, the intermediate radical formed during the reaction of the macroradical and the inhibitor molecule may enter into a chain regeneration with one monomer molecule. The experimental bases of this hypothesis,i.e., the vibrational excitation of the reaction products, the probability of vibrational energy transfer, the deviation from the MAXWELL‐BOLTZMANNdistribution in reacting systems, were discussed. A survey has been given of a few hot‐radical reactions of the gaseous phase and the question has been examined whether there is, in principle, a possibility for “hot effects” to occur in reactions of the liqui

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790102

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractDarstellung, Konstitution und Eigenschaften von drei neuen Diglycidäthern auf der Grundlage von Polyphenolen, Derivaten des α,α′‐ und β,β′‐Dihydroxydinaphthyls sowie β,β′‐Dihydroxydinaphthylmethans werden beschrieben. Durch Elementaranalyse, Molekulargewichtsbestimmung, Epoxydgruppengehalt und IR‐Spektrum wurde die Struktur der dargestel

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790103

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractIn the polymerization of propylene oxide by the diethylzine(+)borneol system, the crystalline polymer formed was optically active, dextrorotatory in chloroform and levorotatory in benzene. Recovered monomer was levorotatory. By taking material balance in terms of optical rotation between the crystalline polymer and recovered monomer, the formation of the optically active polymer by the present catalyst is considered to be due to the preferential incorporation of the L‐antipode in the polymer chain. Proposed initiation and chain transfer steps were examined using14C‐methanol and methanol‐3H as alcohol component of the catalyst s

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790104

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractDie Ultrazentrifugen‐Methode von ARCHIBALD gibt dieselben Information über hochpolymere Lösungen wie die Lichtstreuungsmethode; sie liefert das Gewichtsmittel des Molekulargewichtes und den zweiten osmotischen Virialkoeffizienten. Diese Methode hat jedoch einen Nachteil, insbesondere bei Untersuchung der Polymeren in guten Lösungsmitteln; die Auftragung der Meßdaten nach der Theorie weist oft eine ausgeprägte, nach oben gerichtete Krümmung auf, wodurch die Extrapolation auf die Konzentration Null schwierig wird. Es wurde daher ein halbempirisches Verfahren vorgeschlagen, um diese Schwierigkeit zu vermeiden7. Wir haben nunmehr das Verfahren durch Messungen an Lösungen von Polystyrol und Polymethylmethacrylat in guten Lösungsmitteln überprüft und die erhaltenen Molekulargewichte und zweiten Virialkoeffizienten mit den bisherigen Daten anderer Autoren

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790105

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractEs wird gezeigt, daß bei der Wasseraufnahme von Ionenaustauschern deutlich voneinander abgegrenzte Hydrationszustände vorliegen. Die mit Wasserstoffionen beladenen Austauscher nehmen bis zur Dissoziation 2 Wassermolekeln auf, die mit Chlorionen beladenen (Anionenaustauscher) 3 und die mit Kalium‐ bzw. Natriumionen beladenen 4. Auf Grund der spezifischen Polarisation kann man wesentliche Unterschiede in der Ausbildung der einzelnen Hydratationszustände erke

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790106

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractExperimental data on the molecular weight and ionic strength dependences of molecular parameters of sodium carboxymethyl cellulose (NaCMC) are discussed and interpreted using current theories.Unperturbed dimensions of NaCMC have been calculated from viscosity‐molecular weight data using the STOCKMAYER‐FIXMAN theory. The KUHN equivalent chain segment length, Am, and the ratio$$(\text{\bar R}_\text{0}^\texxt{2} /\text{\bar R}_\text{F}^\text{2} )^{1/2}$$shows that NaCMC is a typical flexible polymer in the unperturbed state.At infinite ionic strength, NaCMC is a flexible, randomly coiling chain with dimensions appreciably exceeding those in the unperturbed state; this difference is attributed to solvation of the chain. The extension is, however, smaller than that for the non‐ionic derivative hydroxyethyl cellulose.At low ionic strength, the model approximated by the molecule is that of an extended coil; there is, however, still considerable hydrodynamic interaction between segments. Possible reasons are discussed for the difference between the magnitudes of the observed virial coefficients and those calculated using recent theories.The theories of polyelectrolyte expansion are found to be unsatisfactory in predicting the extension of NaCMC in solutions of different ionic strengths. With most of the relationships used, the difference between the observed and calculated expansions was equivalent to a binding of approximately two‐thirds of the coun

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790107

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractThe IR active normal vibrations oferythro‐ andthreo‐di‐isotactic poly(propylene‐1‐d1) were discussed. The calculated frequencies were compared with the polarized IR spectra observed by PERALDO and FARINA. Poly(propylene‐1‐d1‐cis) and poly(propylene‐1‐d1‐trans) areerythro‐ andthreo‐di‐isotactic, respectively. Accordingly, the polymerization of propylene with ZIEGLER‐NATTA catalysts occurs bycis‐opening of the double bonds. The potential energy distribution was calculated and the nature of the

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790108

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractEs wurde der thermische Abbau von Poly‐α‐methylstyrolen verschiedener Taktizität in Substanz unter Stickstoff bei Temperaturen zwischen 220 und 240°C untersucht. Dabei wurde gefunden, daß die kationisch hergestellten, hochgradig syndiotaktischen Polymeren wesentlich langsamer depolymerisieren als die fast ataktischen, anionisch hergestellten Poly‐α‐methylstyrole. Die Ergebnisse beim Abbau von Poly‐α‐methylstyrolen mit verschiedenen Endgruppen machen neben dem hauptsächlich durch statistische Kettenspaltung erfolgenden Abbau auch einen teilweise am Kettenende einsetzenden Ab

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790109

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractThe cationic polymerization of 3,3‐dimethyl‐1‐butene (t‐butyl ethylene) has been investigated. Polymerizations were carried out with AlCl3catalyst in ethyl chloride solvent in the temperature range −31 to −130°C. Trimers (viscous oils or soft gels) were obtained between −31 and −100°C. The composition and structure of these materials is complicated and remains obscure. Solid polymer was obtained only at −130°C. This material, whose degree of polymerization is ∼ 68, is a white amorphous powder and it melts between 55 and 66°C. It is soluble in most common solvents.Careful NMR and IR spectroscopic studies indicate that the repeat struc

ISSN:0025-116X    

DOI:10.1002/macp.1964.020790110

出版商:Hüthig&Wepf Verlag    

年代:1964

数据来源: WILEY