摘要:

Abstract1.3‐Cycloaddition reactions were used for the polyaddition of bisdiazoalkanes and bisazides with different bis‐dipolarophiles.1.6‐bisdiazohexane CHN2(CH2)4CHN2was condensed with biscyclopentadienequinone, hexamethylene‐ andm‐phenylene bismaleimide; Δ1‐pyrazoline addition products are obtained. However withp‐benzoquinone andp‐diethynylbenzene a Δ2‐pyrazoline and a Δ2‐pyrazoline and a Δ2‐pyrazol condensation product were obtained, respectively.Similarly 1.4‐ and 1.3‐bis‐(α‐diazobenzyl)benzenes Ph2CN2C6H4CN2Ph2have been condensed with N.N′‐hexamethylene‐ andm‐phenylene bismaleimide, and the NMR and infrared spectra of the polymers compared with those of the condensation products of diphenyldiazomethane with the same two bisdipolarophiles. This comparison demonstrates a cyclopropane structure for the addition products.On the other hand 1.4‐diazidobenzene was condensed with 1.4‐diethynylbenzene N.N′‐hexamethylene‐ and N.N′‐m‐phenylene bismaleimide, giving respectively a polyphenyl triazol derivative, and products containing mainly phenyl and aziridine rings.As expected the polyaromatic systems melt at higher temperature and are more thermostable in the

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170101

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractThe general combinatorial expression of the partition function for a polymer chain with neighbour interactions is given. It is shown how to take into account the existence of linear relationships connecting the frequencies of some conformational states of the monomer units. Such restrictions may be introduced when external factors influence the conformational equilibrium. The equivalence of the combinatorial and the matrix approach is proved; applications to the copolymer problem as well as to polyelectrolytes in solution are discussed.

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170102

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractIt is shown here how the theory proposed in the preceding paper may be applied to the conformational analysis of atactic polymers as well as of oligomers in solution. The calculation of the free mean‐square lengths of polypropylenes with various types and degrees of tacticity is discussed in detail. In particular, the chain distributions ofdandIunits, coresponding to the models taken into consideration, are closely represented by the MARKOFFian law. The agreement between our results and those obtained by FLORYetal. through Monte‐Carlo calculations is substantially good. The reasons why the configurational defects in nearly isotactic poly‐α‐olefins should be more closely represented by the (…dddlddd…) sequences than by the (…dddlll…) ones proposed by

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170103

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractEs wird eine Erklärung für den bcobachteten Einfluß der Aufheizgeschwindigkeit auf die Aktivierungsenergie der thermischen Zersetzungsreaktionen von Polymeren unter thermogravimetrischen Bedingungen gegeben. Dabei wird gezeigt, daß bei komplexen Reaktionen (zu denen auch die Depolymerisationsprozesse zählen) die bekannte Verschiebung des Zersetzungstemperaturbereiches mit der Aufheizgeschwindigkeit nicht parallel verlaufen kann, falls mit einem Einfluß des Umsetzungsgrades auf die Aktivierangsenergie zu rechnen ist. Unter thermogravimetrischen Bedingungen wird aber immer solch ein Einfluß bei komplexen Reaktionen zu beobachten sein, da sich infolge des Temperaturanstieges nichtstationäre Reaktionsbedingungen einstellen köunen. Eine Änderung der Neigung der Umsatzkurven für verschiedene Aufheizgeschwindigkeiten bedeutet aber eine Änderung des Temperaturkoeffizienten und somit auch der Aktivierungsenergie. Dadurch wird aber die tbermogravimetrische Analysenmethode eine wertvolle Methode zur Unterscheidung von einfachen und komplexen Reaktionen, da einfache Reaktionen keine vorn Umsatz abhängige Änderung der Aktivierungsenergie aufweisen und somit weder eine Neigungsänderung, der verschobenen Umsatzkurven noch eine Äderung der Aktivierungsenergie mit der Aufheizgeschwindigk

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170104

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractThe effects of the concentrations of monomer, cyclohexanol, V5+, H2SO4, HSO −4, SO 2−4, Cl−and ionic strength at 40 to 60°C on the rate of V5+disappearance and the rate of polymerisation of acrylonitrile were studied. From the experimental results, it was concluded that the organic free radicals formed during the decomposition of the V5+‐cyclohexanol complex, initiated polymerisation and that the polymer radicals were terminated by V5+ion. An appropriate kinetic scheme was proposed and the various rate and energy parameters we

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170105

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

Abstractα‐Methylstyrol wurde, mit Natriumnaphthalin in Tetrahydrofuran (THF)bei −78°C polymerisiert. Bei einem konstanten Verhältnis Monomeres/Lösungsmittel 1:10 (vol/vol) nimmt der Anteil Tian isotaktischen Triaden mit steigendem Verhältnis Monomeres/Initiator (steigendem Molekulargewicht des Polymeren) von Ti= 0,35 (M = 2700) auf Ti= 0,56 (M>2·105) zu und der Anteil an heterotaktischen Triaden von Th= 0,22 (M = 2700) auf Th= 0,10 (M>20000) ab. Der Anteil Tsan syndiotaktischen Triaden ist bei M2·105) ab. Bei teilweisem Ersatz von Tetrahydrofuran durch Hexan bzw. völligem Ersatz durch Tetrahydropyran als Lösungsmittel bei der Polymerisation nimmt Tizu, vor allem bei niedrigen Molekulargewichten. Proben mit M<3000 sind nach dampfdruckosmotischen Messungen in Benzol, Cyclohexan und Chloroform bei 37°C assoziiert. Die Assoziation folgt wahrscheinlich dem Unimer/‐N‐Mer‐Typ. Die Viskositäts/Molekulargewichts‐Beziehung [η] KM awzeiat für THF Toluol und Cyclohexan Anomalien unterhalb Mw= 45000. Im gleichen Bereich ändert auch die Funktion Tg= f (1/Mw) ihre Neigung. Die Glastemperatur Tgniedermolekularer Polymerer wird durch Polymerisation in Mischun

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170106

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractThe polymerization of furfuryl methacrylate (FMA) and carbomethoxyfurfuryl methacrylate (CMFMA) has been studied. It has been established that under equal conditions the rate of CMFMA polymerization is greater than the rate of polymerization of FMA. The temperature dependence of the rate constants showed that the polymerization of FMA is associated with a greater energy of activation.These results are explained by π‐complex formation between the furan nuclei on the one hand and the methacrylic double bonds or the growing methacrylic radicals on the other. Complex stability depends on the electron‐donor capacity of the furan nu

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170107

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractThe present paper describes the ternary catalyst system consisting of Group II metal halides, AlEt3, and CCl4, which initiatesatroom temperature the polymerizations of ethylene (60 atmospheres), styrene, vinyl acetate, methyl methacrylate, acrylonitrile, and isobutyl vinyl ether. As the component of Group II metal halide, ZnCl2, ZnI2, CdCl2, MgCl2, and BeCl2were effective. This catalyst system induced the cationic polymerization of vinyl ether. On the other hand, the copolymer composition curve of the styrene‐methacrylate copolymerization with this catalyst system was close to that of free radical copolymerization. In addition, this catalyst system has also been characterized by the 1:1 alternating copolymerization of ethylene with vinyl acetate at room temperatur

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170108

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractViscosity and NMR studies of poly‐1‐vinylnaphthalene, (PIVN), poly‐2‐vinylnaphthalene, (P2VN), and poly‐vinylbiphenyl, (PVB) solutions were carried out over a range of temperatures and molecular weights. For these polymers as well as polystyrene the viscosities at finite concentrations indicate two transition regions at about 20 and 50°C. At infinite dilution no transitions were observable except for P2VN, where a transition region around 45°C was noted. From the temperature and molecular weight dependence of [η], the conformational parameter σ = (〈r 2Θ〉/〈r 2of〉)1/2, interaction parameter B and their temperature dependence are obtained. For P1VN and P2VN, dσ/dT<0, whereas the opposite holds for PVB. At 30°C, σ is a linear function of the volume of the pendant group. The transition observed by viscosity and NMR is not reflected in B. For P2VN and PVB dB/dT0. From the NMR studies of P2VN solutions the activation energy of the main transition at 50° is calculated as E = 23 ± 4 kcal/mole for 100% polymer, indicating strong hindrance of motions. The transition has been ascribed t

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170109

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractUsing methyl 1‐methyl‐2‐(9′‐anthryl)‐cyclopropyl‐carboxylate as initiator, the polymerization of methyl methacrylate in benzene or in bulk was carried out at 70°C. It was found that the rate of polymerization, Rp, was expressed by the Eq. (1)\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm R}_{\rm p} = {\rm K}\left[ {\rm K} \right]^{{\rm 0.82}} \left[ {\rm M} \right]^{1.5} $$\end{document}where [K] and [M]are the concentrations of the initiator and the monomer. Assuming that termination step consists of reaction of a polymer radical with the initiator and of bimolecular and monomolecular terminations, the Eq. (2) was derived.\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm R}_{\rm p} = - {\rm A}\left[ {\rm K} \right]\left[ {\rm M} \right] + {\rm B}\left[ {\rm K} \right]^{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} \left[ {\rm M} \right]^{{3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-\nulldelimiterspace} 2}} + {\rm C}\left[ {\rm K} \right]^{{3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-\nulldelimiterspace} 2}} \left[ {\rm M} \right]^{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} $

ISSN:0025-116X    

DOI:10.1002/macp.1968.021170110

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY