摘要:

AbstractThe preparation of defined one and two component networks by simultaneous copolymerization and crosslinking is described as well as the calculation of the crosslink density and the number of elastically active chains from copolymerization data. The two component networks built up in this manner consist of a polymer backbone formed by one polymer component, which is crosslinked by bridges of another polymer of varying length. Such networks in the swollen state, using water as solvent, can be treated within the framework of existing swelling and mechanical theories. The information derived from copolymerization data is compared critically with those derived from equilibrium swelling and deformation behaviour. In addition, NMR‐spin‐lattice relaxation data are discussed, which give some insight into the relative affinity of each polymer for the solvent. Finally an expression for the activity of the solvent in the network phase as result of swelling of a two component network is given.The crosslinked graft copolymers discussed in this paper consist of poly‐(N‐vinyl‐2‐pyrrolidone) as the backbone and poly(ethylene glycol) as the interconnecting bridge.Conclusions derived from the two component hydrogel studies should be relevant for non‐hydrophilic two component

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950101

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractUntersucht wurden Veränderungen der Faserstruktur und der Adsorption von Direktfarbstoffen in Baumwolle, die verschiedenen Arten der Mercerisation und Flüssigammoniak‐Behandlung unterworfen wurde. Daraus ergaben sich neue allgemeine Zusammenhänge zwischen Farbstoffadsorption und Faserstruktur bei Cellulosefasern. Die Charakterisierung der Faserstruktur erfolgte im wassergequollenen Zustand durch Bestimmung des spezifischen Porenvolumens, der spezifischen Porenoberfläche und der Porenverteilung. Das färberische Verhalten der verschieden behandelten Baumwolle wurde durch Aufnahme von Adsorptionsisothermen bestimmt. Es zeigte sich, daß für die Farbstoffadsorption im Gleichgewicht in erster Linie ein übergangsporenbereich von ca. 20–60Å Durchmesser in der Faser verantwortlich ist, dessen Veränderung durch die verschiedenen Quellungsbehandlungen direkt mit der Farbstoffaufnahme korreliert. Diesen Porenbereich findet man in der Baumwolle zwischen den kristallinen Eleme

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950102

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractThe formation mechanism of anisotropic polymer membranes formed by a system of cellulose nitrate (CN)/n‐propyl alcohol (n‐PrOH)/N,N‐dimethyl formamide (DMF) was investigated. The ultrafiltration characteristics and the membrane structure were influenced significantly by the casting solvents (ratio of n‐PrOH to DMF) and the evaporation period during the membrane formation process. The finger‐like structure in the sponge layer was observed in all systems except that of n‐PrOH/DMF = 2/1 and increased with the evaporation period, after 2 min in the system of pure DMF and after 5 min in the system of n‐PrOH/DMF = 1/3. The formation mechanism of the anisotropic CN membranes and the ultrafiltration characteristics were discus

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950103

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractThe permeation characteristics and the formation mechanisms of poly(vinylidene fluoride) (PVF2) membranes were investigated by changing the casting solvent and the exposure period in the preparation conditions of the membranes. Changes of the microporous structure of the resulting membranes with the exposure period are dependent on differences in forming coacervated droplets based on phase separation. Changes of the permeation characteristics and the formation of coacervation by changing the combination of the mixed solvents are related to differences of the form of PVF2molecules in the casting solution, to differences of the formation of surface layer with the evaporation of a low and a high boiling point solvent, and to differences of the hygroscopicity of the high boiling point solvent.

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950104

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractThe extent and rate of dyeing with some direct and reactive dyes for cellulose copolymerized with polystyrene, poly(methyl vinyl pyridine), and poly(methyl methacrylate) were studied. It was found that regardless of the dye used, the extent and rate of dyeing for the first two copolymers were substantially higher than the control (nonmodified cellulose). The opposite holds true for cellulose‐poly(methyl methacrylate) graft copolymer. It was also found that the extent of dyeing depended upon the magnitude of grafting within the range studied. The results were interpreted in terms of changes in the physical and/or chemical structure of cellulose brought about by grafting as well as nature of the graf

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950105

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractNous avons fait réagir, en présence de diphényl‐méthane diisocyanate et de butane diol (1,4), des oligomères α‐ω dihydroxylés du butadiène et de l'isoprène hydrogénés à différents taux. Les polyuréthannes segmentés ainsi obtenus ont fait l'objet d'études mécaniques dynamiques et statiques. Ceux synthétisés à partir d'oligobutadiènes de microstructure (1,4) majoritaire présentent une forte diminution de leur pouvoir amortissant et une seconde relaxation due à la structure semicristalline de la séquence souple après l'hydrogénation de cette séquence. L'hydrogénation des oligomères (1,2) confère par contre aux polyuréthannes de meillures propriétés d'élastomères, une relaxation de la phase souple décalée vers les basses températures ainsiqu'une meilleure tenue aux hautes températures. Ces modifications semblent pouvoir ětre attribuées à une meilleure ségrégation de phase entre

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950106

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractSynthetische Polyamide wie Polycaprolactam und Poly(hexamethylenadipamid) sind im trockenen Zustand hartspröde Formmassen. Durch ein Zulegieren von Polyolefinen kann die Schlag‐ und Schockfestigkeit im trockenen Zustand wesentlich verbessert werden. Beschrieben werden die Arbeiten zur Strukturaufklärung dieser makromolekularen Mehrstoffsysteme, die zeigen, daß man optimale Ergebnisse erzielt, wenn in der kontinuierlichen Polyamidmatrix Polyolefinpartikelchen mit einer Größe von etwa 0,5 bis 5 μm eingebettet sind und an der Phasengrenzfläche durch Blockpfropfcopolymerisate eine Haftung und damit eine Verträglichkeit der nicht mischbaren Komponenten erre

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950107

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractBy the method of design of experiments it was investigated the effect of some components of polymerization feed as the content of inert components, crosslinking agent, initiator, thermodynamic quality of inert components and polymerization temperature on the specific surface area of the produced sorbents which were copolymers from glycidylmethacrylate and ethylenedimethacrylate. By varying the five parameters given above, it was possible to control the specific surface area within the range 0–460 m2g

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950108

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractBy the method of design of experiments, the influence of the content and the thermodynamic quality of the mixture of inert solvents (porogenic compounds), of the concentration of the crosslinking agent and initiator in the polymerization mixture and of the reaction temperature in the radical suspension copolymerization was investigated with respect to the pore size, the porosity and the mechanical properties of macroporous copolymers from glycidylmethacrylate and ethylenedimethacrylate. It was found that the predominant effect on these characteristics should be attributed to the volume of the porogenic component in the mixture, and that the pore size and porosity increase at the same time the penetration modulus and the stress‐at‐break decrease proportionately to this volume. The concentration of the crosslinking agent has an influence only at low crosslinking values. The polymerization temperature and concentration of the initiator have only an insignificant effect on the structure and mechanical propert

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950109

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractThe internal structure of polymeric sorbents based on 2,3‐epoxypropyl methacrylateethylene dimethacrylate was investigated by means of mercury porosimetry and by employing the sorption method. The results were confronted with characteristic chromatographic data and helped to elucidate the relationships existing between the internal structure of copolymers and their chromatographic propertie

ISSN:0003-3146    

DOI:10.1002/apmc.1981.050950110

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY