摘要:

AbstractRadiation‐induced graft copolymerization of 4‐vinyl pyridine (VP) and a binary mixture of VP and acrylonitrile (AN) onto polyamide‐6 (PA6) fiber has been studied. Optimum reaction conditions leading to maximum percentage of grafting have been evaluated. The graft copolymers have been characterized by IR spectroscopy, thermogravimetric analysis and also by studying the dyeing behaviour of the grafted and ungrafted fiber. It has been observed that, although the thermal properties of fibers had changed upon grafting, the dyeing behaviour, with respect to the total dye uptake, did show only little improv

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340101

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe synthesis, characterization and coordination aspects of the title polymer ligands are reported. The polymeric chelates were prepared by polycondensations of transition metal ions (M) with a poly(Schiff's base) (L). The analytical data propose a (ML)nformula for the chelates. All the polychelates are stable and insoluble in common organic solvents. The geometry around the central metal ion in each chelate is proposed on the basis of measurements of magnetic susceptibilities and UV reflectance spectra. The ligand field splitting parameters 10 Dq, the interelectronic repulsion parameter B, the nephelauxetric parameter β and ligand field splitting energies (L.F.S.E.) have been calculated for Ni(II) and Co(II) chelates. All chelates are resistant to moderately concentrated acids and dilute alkalies at ambient temperature. They exhibit thermal stabilities to varying degrees. IR spectra show that the ligand usually coordinates via the carbonyl oxygen (C=O) and the phenolic OH with replacement of hydrogen by metal ions

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340102

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe effect of plasma treatment of porous polyacrylonitrile membranes is discussed. It is shown that air plasma increases the surface polarity at low‐energy treatment and gradually diminishes it when the energy is increased. When the plasma is set at energies of 12, 30 or 60 W, etching of polymers dominates. Pore diameters of the membranes increase and their distribution functions become broader. When plasma of higher energies (120 or 180 W) is used, the effect of changes of the pore distribution disappears. Membranes modified with plasma of 60, 120 or 180 W do not differ in their porous structure. A simple method of an evaluation of pore diameter distribution function is presente

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340103

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractSulfatations of cellulose and of other types of polysaccharides by the salts of acids H2SnO2n+1and H2SnO3n+1in DMF/N2O4medium have been carried out. Uniformly substituted biologically active sulfates of polysaccharides have been obtained.

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340104

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe characteristics of permeation and separation for aqueous solutions of methanol and ethanol through a poly[bis(2,2,2‐trifluoroethoxy)phosphazene] (PBTFP) membrane were studied by pervaporation and evapomeation. In pervaporation technique, methanol was preferentially permeated in all of the feed solution compositions and ethanol was permeated in lower ethanol concentrations of the feed solution. Water was predominantly permeated from the feed solutions with higher ethanol concentration. In evapomeation technique, water was selectively permeated in both all of the feed vapor compositions for aqueous methanol and ethanol solutions. These different permselectivities depended on the feed composition and the membrane permeation technique and could be discussed by a difference in the mechanisms of permeation and separation. It was found that the permeation rate was influenced remarkably by the degree of swelling of the PBTFP membrane and the permselectivity for water of aqueous alcoholic solutions was enhanced by an increasing degree of swelling of the membrane. When the degree of swelling of the membrane with rising permeation temperature was small, both the permeation rate and permselectivity for alcohol in pervaporation and evapomeation increased with the permeation temperature. The above results are discussed considering the PBTFP membrane structure in evapomeation and pervaporatio

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340105

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractHybrid carbon‐glass fiber composites of novolak epoxy‐based vinyl ester resins have been investigated. The chemical resistance, the thermo‐oxidative stability and the mechanical properties such as tensile strength and tensile modulus, as well as flexural strength and flexural modulus, interlaminar shear strength (ILSS) and impact strength have also been estimated. The combination of glass and carbon fibers in the hybrid turns out to be an excellent mix. These composites have good tensile and flexural properties as well as the good chemical resistance of the carbon fibers and the high impact strength of the glass fibers and also the thermo‐oxidative stability of highly aromatic vinyl ester resins based on novola

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340106

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe formation of styrene‐maleic anhydride‐methyl methacrylate terpolymers was studied in batch polymerization process. The process of polymerization was investigated in quasi‐steady‐state time periods by the Markov statistics. The results of the calculations for high conversions were compared with the experimental results. Based on the advantage of the method, PVC blends were produced which (with 40% of blend component) increased the Vicat‐A and Vicat‐B heat‐resistance of PVC by 40–43°C and 18–

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340107

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractStructural investigations of low‐molecular‐weight polyisobutenes synthesized by selective polymerization and of commercial polyisobutenes were made by1H‐ and13C‐NMR spectroscopy. It is possible to attribute the signals to “normal” and to some unusual olefinic structures. A comparison was made to lite

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340108

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractNew polymers were synthesized by addition of epichlorohydrin to the polyamides or poly(amideimide)s derived from the polycondensation of poly(alkylenepolyamide)s with some Diels‐Alder adducts of resin acids. The adducts were prepared by the reaction between resin acids (extracted from rosin) and acrylic acid or maleic anhydride. The obtained polymers, which were investigated by usual physical and chemical methods, are three‐dimensional, thermosetting and fairly thermosta

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340109

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractMultiblock‐(AB)n‐copolymers, consisting of hard segments of poly(butylene terephthalate) (PBT) and soft segments of dimerized fatty acid were synthesized and analysed with DSC and DMTA. The polymers were characterized by their limiting viscosity number and melt flow index. The glass transition temperature (Tg) and melting temperature (Tm) increase with decreasing weight fraction of the dimerized fatty acid and with the increase of the crystalline phase content. It was found that the elasticity (ϵ) depends on the content of dimerized fatty acid in the amorphous phase. Tensile properties were described as a function of the degree of polycondensation Pk(molecular wei

ISSN:0003-3146    

DOI:10.1002/apmc.1996.052340110

出版商:Hüthig&Wepf Verlag    

年代:1996

数据来源: WILEY