摘要:

AbstractDie Copolymerisation von Acrylamid mit den Vinylestern der 2,4‐Dichlorphenoxyessigsäure und 2,4‐Dichlorphenoxybuttersäure wurde untersucht in der Absicht, in der Landwirtschaft einsetzbare Präparate mit verlängerter, das Wachsum regulierender ktivität herzustellen. Neben einigen kinetischen Messungen wurden die Copolymerisations‐parameer ermittelt. Für das System Acrylamid‐Vinylester der 2,4‐Dichlorphenoxyessigsäure ergab sich r1= 4,08 ± 0,08 undr r2= 0,943 ± 0,16; für das System Acrylamid‐Vinylester der 2,4‐Dichlorphenoxybuttersäre ergab sich r1= 1,50 ± 0,09 und r2= 1,02 ± 0,18. Die Bedingungen, bei denen wasserlösliche Copolymere mit guter Ausbeute bei genügend hohem Gehalt an physiologisch aktiven Glieder

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660101

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractIndian Chokla wool was treated with five different kinds of metallic ions (Fe3+, Mn3+, Ce4+, V5+, Cr6+), and the adsorptive behaviour was studied to elucidate the manner in which wool and the metallic ions were combined. The effect of time of treatment, concentration and temperature upon the amount of the metallic ions adsorbed were examined. Considering the various factors it is suggested that chelate bonds are formed between the metallic ions and the groups present in wool.

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660102

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractBei der Umsetzung zwischen Stabilisatoren aus Carbonsäresalzen zwewertiger Metalle and PVC während der Hitzestabilisierung bei 180°C laufen folgende Reaktionen ab:Der Stabilisator bindet abgespaltenen Chlorwasserstoff.Aus einem Komplex zwischen einem Stabilisatormolekül und einem allylständigen Chloratom im Polymeren wird ein Säurerest aus dem Stabilisator gegen das Chloratom ausgetauscht.Der Stabilisator verhindert die Ausbildung von längeren Polyensequenzen, indem eram Ende solcher Sequenzen allylisch gebundene Chloratome in einer Umeserungsreaktion durch Särereste ersetzt.Durch die chemische Bindung von abgespaltenem Chlorwasserstoff wird eine autokatalytische Beschleunigung der weiteren Chlorwasserstoffabspaltung unterdrückt. Gleichzeitig werden für die thermische Instabilität von PVC versantwortliche „labile”︁ Stellen in Polymeren unwirksam gemacht; aus instabilen allylischen Chloratomen entstehen thermostabilere Estergruppen. Ferner wird das Entstehen längerer, im sichtbaren Bereich des Spektrums absorbierender Polyenseq

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660103

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractA new method for the determination of the swelling pressure πsof gels is presented. The gel remains in the isotropic state when the isothermal mechanical equilibrium is established. The temperature dependence of πscan be measured at constant composition. The applicability of the method is demonstrated for chemically crosslinked gelatine swollen in wate

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660104

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractA model series of ordering of submicroscopic spherical particles forming the basic structure of macroporous copolymers is suggested by analogy with elementary crystallographic lattices. This series with various porosity (p=25.95‐78.53%) allows not only the calculation of the mean radius of submicroscopic particles, but also a better choice of the coefficient used in calculating the mean pore radius from specific pore volumes and specific surfaces. A general method of calculation of the mean particle radius and of the mean pore radius for macroporous copolymers is also proposed, and a comparison with real systems is mad

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660105

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractCopolyimides were prepared by reacting 3,3′,4,4′‐benzophenone tetracarboxylic acid dianhydride (BPTD) with mixtures of various proportions of 3,3′‐sulfonylbis (phenyl isocyanate) (SDI) and 4,4′‐methylenebis (phenyl isocyanate) (MDI) in an aprotic polar solvent. The nature and properties of these copolyimides

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660106

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractBead macroporous terpolymers of methacrylaldehyde with methyl methacrylate and ethylene dimethacrylate were prepared. Preparation conditions (composition of the monomer mixture, of the inert components, concentration of the initiator and of the suspension stabilizer, and the rate of stirring) were discussed with respect to the properties of the terpolymers (porosity and concentration of reactive aldehyde groups).Concentration of reactive groups in the polymer was controlled by adding a third monomer. The analytically determined differences in the concentration of the reactive groups in the batch and in the polymer were interpreted (a) by the inaccessibility of the groups within the polymer bulk (for polymers with 30–50 mol‐% of crosslinking agent), (b) by the presence of tetrahydropyran rings or acetate bonds between the chains, and (c) by the formation of extractable soluble polymers or copolymers, or by not reacting of parts of the monomers (observed predominantly with low‐crosslinked polymers containing 10 mol‐% of crosslinking

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660107

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe mechanism of the antioxidative effect of thiobisphenols in the inhibition of autoxidation of polyolefins initiated by the decomposition of hydroperoxides was studied by means of a model reaction of 4,4′‐thiobis(2‐methyl‐6‐tert‐butylphenol) (I) with tert‐butylhydroperoxide in the presence CO(II)acetyl acetonate. Products isolated from the reaction mixture prove that in the inhibition of autoxidation, thiobisphenols break as phenols the propagation chains of radical autoxidation, while they decompose as sulphides the hydroperoxides into nonrad

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660108

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe thermal degradation of poly(vinyl chloride) has been investigated in diethyl, dibutyl and dioctyl maleate under nitrogen from 160°C to 210°C. The rate of dehydrochlorination was highest in dibutyl maleate and lowest in dioctyl maleate. The apparent activation energy calculated from the average value of the rate constant at each temperature for diethyl, dibutyl and dioctyl maleate was found to be 83.6 kJ mole−1, 112.7 kJ mole−1, and 150.5 kJ mole−1, respectively. The rates of dehydrochlorination and the activation energy observed in alkyl maleates are higher than those observed in ethyl benzoate. In the visible range spectra the absorption at higher wavelengths is considerably reduced in alkyl m

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660109

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractAus Rinderplacenten hergestellte lösliche Kollagen‐Präparate werden durch Hydroxyprolin‐Bestimmung, Gesamtaminosäureanalyse, Viskositätszahl, Denaturierungstemperatur sowie Untersuchung im Transmissions‐ und Rasterelektronenmikroskop charak

ISSN:0003-3146    

DOI:10.1002/apmc.1978.050660110

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY