摘要:

AbstractDie Aushärtung von Mischungen aus Hexahydrophthalsäureanhydrid mit Dicyclopentadiendioxid bzw. mit einem. niedermolekularen Epoxyharz wurde mit Hilfe der Infrarotspektroskopie verfolgt. Dabei zeigte sich, daß diese Reaktion durch Alkalihalogenide, also z. B. auch durch die üblichen NaCI‐Fenster, beschleunigt wird. LiCl ist besonders wirkung

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110101

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractIn the presence of ferric ion, polymerization of acrylamide initiated with ceric ion was studied. The resulting polyacrylamide was found to contain cerium and iron, and the total metal content of the polymer corresponded to one atom per macromolecule. Experimental data of paper electrophoresis, polarography and IR spectroscopy suggested that the metals combined chemically with the polymer molecule. A probable mechanism of introduction of the metal into the polymer chain is discussed.

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110102

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractPolyethylmethacrylate (PEM) was prepared by bulk polymerization and fractionated using acetone/acetone‐water (2:1 V/V) mixture. The solution properties of fractionated as well as unfractionated polymers were investigated in various solvents (ethylacetabte, toluene, ethylacetate‐ethanol) by light scattering and viscosity at 35°C. Osmotic pressure measurements were also carried out on selected polymer samples for the evaluation of width of distribution. [η]–Mwand (r2)1/2–Mwrelationships for these systems were established. Ethylacetate was found to be a bad solvent compared to toluene and methylethyketone. In the case of unfractionated PEM, the parameters like [η]2/3M1/3,Mw/[η], and Φ were corrected for molecular weight heterogeneity assuming SCHULZ‐ZIMM distribution. For the evaluation of FLORY's constant K, and the unperturbed dimension (r 20)1/2of the polymer, FLORY‐FOX, KURATA‐STOCKMAYER, and STOCKMAYER‐FIXMAN methods were employed. The K and (r 20)1/2values evaluated from the FLORY‐FOX method were almost similar to those measured in a Θ solvent, while the other two methods yielded higher values. A comparison of the measured (r2) 1/2wand that calculated from KIRKWOOD‐RISEMAN and DEBYE‐BUECHE theories indicated the polymer coil as conforming to a statistical chain. The molecular weight dependence of A2, the second virial coefficient, for PEM/ethylacetate was established and the value of A2compared well with that calcu

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110103

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractViscometric and osmometric studies have been carried out with fractions of poly(mmethyl styrene) in solutions of benzene, cyclohexane, and ethyl acetate at 30, 40, and 50°C. The values of K′ and ‘a’ in the KUHN‐HOUWINK relation have been reported for the above polymer‐solvent systems. The values of unperturbed dimension, (r 20/M)1/2, solvent polymer interaction constant (B) and conformational parameter (σ) have been computed applying the theories of FLORY‐FOX‐SCHAEFGEN, KURATA‐STOCKMAYER‐ROIG, and STOCK‐MAYER‐FIXMAN. The applicability of the theories of FLORY, KURATAet al.,and PTITSYN has been critically analysed from the dependence of the expansion factor (α) on molecular weight. Values of thermodynamic parameters, Θ, Ψ1,x1, and X

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110104

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractAn absolute X‐ray method for the determination of the crystalline fraction in polymers based on the comparison of the integrated intensities of some of the low order lines of polymers with those of the completely crystalline standard substances, is described. The crystallinity data are obtained for six polymers: 45.6% for isotactic polypropylene, 73% for polyethylene, 52.1% for nylon‐6, 50.8% for nylon‐66, 32% for isotactic polystyrene, and 33.4% for poly‐4‐methylpentene‐1.These data are in a reasonable agreement with the data obtained by the other X‐ray procedures. The accuracy of the method, however, is restricted by the general impossibility to know precisely the structure factors and the corrections to the intensities due to the thermal vibrations of the atoms and lattice

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110105

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractDie phenolischen Hydroxylgruppen molekulareinheitlicher Mehrkernverbindungen mit vier und fünfpKresolbausteinen je Molekül konnten vollständig mit Acrylsäurechlorid in Gegenwart von Triäthylamin verestert werden. Ließ man auf die in siedendem Benzol stark verdünnten mehrafachen Acrylsäureester einen Überschuß an Radikalen aus α.α′‐Azoisobutyrodinitril einwirken, so bildeten sich mit guter Ausbeute molekulareinheitliche, dünnschichtchromatographisch reine Leiteroligomere. Die alkalische Verseifung des Leiteroilgomeren mit vierp‐Kresolbausteinen gab eine molekulareinheitliche Hexaacrylsäure, die als Hexamethylester durch Elementaranalyse und Molekulargewicht charakterisiert wurde; die gefundenen Werte stimmten innerhalb der üblichen Fehlerstreuung mit den berechneten überein. Die durchgeführte Reaktionsfolge ist eine synthetische Matrizenreaktion und vegleichbar mit einer natür

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110106

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractThe graft polymerization of styrene through use of γ‐ray irradiation was carried out in vapour phase onto polyethylene single crystals, bulk films of polyethylene and paraffine crystals. It was found that the grafting yield for a given dosage was much less for polyethylene single crystals than for bulk films. The similar difference was also found between the pure paraffine (n‐tetracosane) and mixed paraffines, and these results were interpreted in the light of crystallinity.In order to characterize the polystyrene branches grafted onto the crystals, a new method based on chain transfer reaction was proposed for obtaining number of the grafted points and the length of the branches and was applied to the graft polymerization onto the polyethylene single crystals.The results were compared with those obtained for the graft polymerization onto paraffine crystals. In the latter case, molecular weight of the graft polymer obtained after extracting paraffines from the whole material could be obtained by assuming the copolymer as polystyrene homopolymer. In both of the cases the polymer branch was very long and the sites of grafting were very few.The crystallinities of the samples measured by a X‐ray diffraction method before and after the grafting showed that the grafting did not practically affect the original crystals. The surfaces of the grafted crystals were also examined by an electron microscope and the result implied that the reaction took place mainly on the surfaces of the cr

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110107

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractHigh pressure radical polymerization of vinylacetate with and without solvents has been investigated in the range of 1–2000 kg/cm2.The pressure has the ability to interrupt an occurrence of branching in bulk polymerization and the overall chain length of polyvinylacetate increases with pressure.In solution polymerization, the magnitude of the activation volume of chain transfer to solvent is in following order: toluene>chlorobenzene>bromobenzene. In both cases, the overall rates of polymerizations and the molecular weights of polymers obtained increased with increasing pressure.The overall activation volumes of vinylacetate polymerization are −17.4 ml/mole without solvent and −12.0 ml/mole in be

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110108

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractRadical polymerizations of itaconic acid were investigated under high pressure up to 5000 kg/cm2in several different solvents.The critical pressures under which polymerization does not take place were determined in each solvent and the relation between the dielectric constant of the solvent and the critical pressure was found to be linear. The overall rate of polymerization increases markedly with pressure and the activation volume indicates fairly large absolute values compared with those of other vinyl compounds.The polymers obtained under high pressure are white and brittle having a somewhat hygroscopic property, are soluble in methanol, dimethylformamide and especially in water, and are insoluble in other organic solvents.

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110109

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY

摘要:

AbstractA study of the polymerization of methyl methacrylate initiated by 9‐anthryldiazomethane (ADM) has been made. The initial rate of polymerization, Rp, followed the equation:\documentclass{article}\pagestyle{empty}\begin{document}$${\rm R}_{\rm p} = {\rm k}[{\rm ADM}]^{0 \sim 0.05} [{\rm MMA}]^{1.86} $$\end{document}This equation may be interpreted by the termination reaction of the growing radical with the primary radical. The rate of decomposition of ADM was measured in bulk or in benzene solution and the following rate equation was obtained:\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm k}_{\rm d} = \left[ {\sec ^{ - 1} } \right] = 5.50 \cdot 10^{12} \exp \left( { - 25.2{{{\rm kcal}} \mathord{\left/ {\vphantom {{{\rm kcal}} {{\rm RT}}}} \right. \kern-\nulldelimiterspace} {{\rm RT}}}} \right) $$\end{documen

ISSN:0025-116X    

DOI:10.1002/macp.1968.021110110

出版商:Hüthig&Wepf Verlag    

年代:1968

数据来源: WILEY