摘要:

AbstractA study was made of the removal of Escherichia coli (E. coli) from water by systems based on insoluble poly(glycidyl methacrylate)‐g‐tetraethylenepentamine and ‐g‐polyethylenimine, i.e., the reaction products of insoluble poly(glycidyl methacrylate) (PGMA) beads with tetraethylenepentamine (TEP) or polyethylenimine having molecular weights of about 600 (PEI600). The polymers (PGMA‐TEP and PGMA‐PEI600) were brought into contact with E. coli in sterilized physiological saline. These polymers made the viable cell numbers decrease in this medium. It was confirmed by observation of polymer surfaces with a scanning electron microscope that this decrease was caused by adsorption of the bacterial cells onto these polymers. The decrease coefficients of viable cell numbers (D) for E. coli by these polymers were 53 ml g−1h−1for PGMA‐TEP and 62 ml g−1h−1for PGMA‐PEI600, being compared with D by other poly

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060101

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractDehydrochlorination rates of PVC in nitrogen atmosphere were determined in the presence of rubber seed oil (RSO), epoxidized rubber seed oil (ERSO), barium soap of rubber seed oil fatty acids and barium soap of epoxidized fatty acid of rubber seed oil. The initial rates of dehydrochlorination and the time required for the degradation to attain 1% conversion showed that the rubber seed oil derivatives exert a stabilizing effect on the degradation of PVC. The order of the stabilizing effect was found to be metal soaps of ERSO

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060102

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractZur Verbesserung der Werkstoffeigenschaften von thermoplastischen Polyurethanen (TPU), wie etwa der Wärmeformbeständigkeit, ist es sinnvoll, ein Blending mit Thermoplasten vorzunehmen. Eine gute Phasenverträglichkeit und Phasenhaftung bei thermodynamisch unverträglichen Blendkomponenten kann durch geeignete reaktive Koppler erreicht werden. Bei den Blends aus TPU and PA6 wird Diisocyanat während der Extrusion in der Schmelze eingebracht. Durch die ablaufenden chemischen Reaktionen werden bei extrudierten und verspritzten Blends und bei aus der Lösung erzeugten Systemen aus Polyesterpolyurethan und PA6 verträglichkeitsverbessernde Wirkungen erreicht. Diese wurden als Folge von mit 4,4′‐Diphenylmethandiisocyanat (MDI) initiierten Reaktionen in der Grenzschicht erkannt, wobei die möglichen Reaktionen mit der PA6‐Phase anhand eines Modellsystems aus der Lösung diskutiert werden. Bei Blends aus Polyetherpolyurethan und PA6 wurde keine Verträglichkeitsvermittlung durch MDI nachgewiesen. Die chemische Charakterisierung der Blends erfolgte durch GPC und FTIR, während die morphologischen Eigenschaften mittels DSC, DMA und Elektronenmikroskopie dok

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060103

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe reaction between the diglycidylether of bisphenol A (DGEBA) and 4,9‐dioxa‐1,12‐dodecanediamine (DDDD) has been studied by means of isothermal and dynamic differential scanning calorimetry. The enthalpy of the reaction of an epoxy group with an amino‐hydrogen has been determined to be 112 ± 5 kJ/mol. A kinetic model has been validated. It involves two competitive mechanisms: one is catalysed by the hydroxy groups initially present on the epoxy chain or generated during the reaction (activation energy 77 ± 5 kJ/mol), the other is not catalysed with a higher activation energy (103 ± 3 kJ/mol).For each isothermal curing, the kinetics are not modified by gelation. Evaluated from the gel times, the overall activation energy of the reaction is equal to 62

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060104

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe effect of composition and chemical structure of addition polyimides on thermal characteristics was investigated using commercially available allyl nadic‐imide resins and phosphorus‐containing nadimide resins. Thermogravimetric analysis, in N2atmosphere, of resins cured at 300°C for 1 h revealed improvement of thermal stabi

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060105

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractFlame‐retardant poly(pyromellitic imide aryl phosphoramide‐ester)s were synthesized by interfacial polycondensation of N,N′‐bis(p‐hydroxyphenyl)pyromellitic diimide with aryl phosphoramidic dichlorides. The polymers were characterized by IR and1H‐NMR spectroscopy. The molecular composition was confirmed by elemental analysis. The thermal stability and flammability of the polymers were studied by thermogravimetry and limiting oxygen index, r

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060106

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractCopolymerization of poly(ethylene glycol) macromonomers with terminal meth‐acryloyl groups with styrene was carried out in the presence of 2,2′‐azobis(N,N′‐dimethyleneisobutyramidine) in ethanol/water mixture (4:1, v/v) at various temperatures. The overall activation energy for the dispersion copolymerization was obtained as

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060107

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThis work deals with some features of the reaction of dextran with ethyl chloroformate using triethylamine as catalyst. The presence of cyclic and acyclic carbonate groups in the resulting modified dextrans was demonstrated by IR,1H and13C NMR spectroscopy. Preliminary experiments have shown that the reaction of cyclic carbonate groups with several model amines is greatly dependent on the basic character of the amine. Model amino type drugs (Phenethylamine and tyramine) were quantitatively bound to activated dextran with cyclic carbonate groups. The heterogeneous hydrolysis of dextran‐phenethylamine or dextran‐tyramine adducts showed that no hydrolysis takes place under the applied conditi

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060108

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractA new polyurethane cationomer with pendent azo groups bounds to quaternary nitrogen atoms has been synthesized by polyaddition reaction between poly(tetramethylene oxide) (PTMO), 4,4′‐bibenzyldiisocyanate and N‐methyldiethanolamine, followed by quaternization of tertiary nitrogen with 4‐(3‐chloropropionyloxy)azobenzene.E–Z photoisomerization of azo chromophores by UV irradiation with a high pressure mercury lamp and Z–E thermal relaxation were studied both in solution and film. An azo urethane model and a synthetic mixture of polyurethane cationomer with azobenzene were used f

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060109

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe excimer laser‐induced ablation of triazene polymers at a wavelength of 308 nm has been investigated as a function of laser fluence deposited on the surface in one or several pulses. PMMA, which as a homopolymer can not be ablated at 308 nm, has been sensitized for ablation at this wavelength by synthesizing a copolymer in which 0.3 mol‐% of the side chains contain the triazene functional groups. The high ablated depths per pulse achieved in this manner are similar to the ones observed upon physical doping of PMMA with monomeric triazene compounds. In an alternative approach, the triazene functional group is introduced once (polymer TP 1) or twice (TP 2) into each repeating unit of the polymer backbone by a polycondensation reaction. Irradiation of TP 1 gives rise to ill‐defined ablation profiles with sloping wall. In contrast, clean circular ablation profiles are obtained with polymer TP 2, which are characterized by circular contours, steep edges, and flat bottoms of the ablated craters. The origins of these differences are investigated. A comparative study of excimer laser ablation of TP 2 at 248 and 308 nm shows that the latter wavelength is more effective; the plateau value of the ablated depth per pulse corresponds to ≈ 1 μm at 248 nm and ≈ 3 μm at 308 nm. This dependence is attributed to the photolysis behaviour of the triazene compounds: nitrogen released upon photolytic bond cleavage acts as a driving gas which promotes the ablation. As a consequence, no ‘incubation pulses’ are required for triazene polymer ablation in the investigate

ISSN:0003-3146    

DOI:10.1002/apmc.1993.052060110

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY