摘要:

AbstractPoly(2,5‐thiophenediyl) (2) was prepared electrochemically from 2,2′;5′,2″‐terthienyl (1) on various metal electrodes (Pt, Au, Ni, Ni sputtered with Au) in acetonitrile, with tetrabutylammonium perchlorate as an electrolyte salt under application of varying temperatures (−5°C, room temperature) and current densities (0.05 to 1 mA/cm2). Coatings with a rough surface structure were formed by higher current densities, whereas low current densities built up a homogeneous, compact and smooth surface structure. Ni electrodes coated with Au formed such smooth surface structures even at higher curre

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430201

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractPoly(vinyl alcohol) films were polarized at different electrical field strengths and temperatures. The peak temperature of the TSDC spectra shifted to higher values with increasing polarizing field strength and polarizing temperature. The activation energies and relaxation parameters of the process were evaluated. Based on the results, the origin of TSDC was attributed to space charge polarization with some contribution of dipole orientation.

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430202

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe method of direct energy transfer was used to study the internal morphology of colloid particles prepared by nonaqueous dispersion polymerization. The particles contained 97 mole‐% poly(methyl methacrylate) and 3 mole‐% poly(isobutylene). Phenanthrene and anthracene were used as donor and acceptor. The results were interpreted in terms of a cross‐over phenomenon in restricted geometries. A new scheme of the morphology is suggested for the colloid part

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430203

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractBy reaction of butadiene styrene rubber with a nitrating mixture alkylaromatic nitrooligomer derivatives are formed. The reaction was carried out in dichloroethane solution for 2 to 5 h at temperature 20 to 50°C. The functional composition of the nitrooligomers in dependence on temperature, reaction time, and composition of the nitrating mixture was determined by means of infrared spectroscopy. It was established that at high concentrations of NO2+the nitration of the aromatic ring is predominant, while at low concentrations the nitration of the hydrocarbon chain prevails

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430204

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThermostabilized poly(acrylonitrile) fibres obtained under different conditions have been investigated by means of ultrasonic measurements. The correlations between ultrasonic velocity, density, and some properties of the fibres are studied. The possibility of using ultrasonic velocity as a parameter for the control of the oxidation process of poly(acrylonitrile) fibres is discussed.

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430205

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe polycondensation of maleic anhydride with poly(ethylene glycol)s of different molecular weights has been examined. At the used reaction conditions the occurrence of some secondary reactions such as polyglycol depolymerization and the addition of glycols to double bonds in the polyesters was established. The possible chemical structure of the obtained unsaturated polyesters is proposed.

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430206

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe ring‐opening polymerization of ϵ‐caprolactone was investigated in dependence on the most important reaction parameters. It was found that the monomer conversion is above all determined by polymerization temperature just as type and concentration of initiator. High yields of polymer can be obtained by initiation with tin(II) carboxylates, tin(II, IV) halogenides and titanium alkylates. The molecular weight of the polymer depends in a complex manner on the reaction conditions because the primary ring‐opening reaction is accompanied by consecutive reactions. The values of molecular weight pass through a m

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430207

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe influence of temperature on the magnitude of the synergetic effect of the catalytic system di(tributyltin)carbodiimide + triethylene diamine in reactions of 2,4‐tolylene diisocyanate with macrodiols has been studied. For calculations of the reaction rate constants a differential‐integral method based on the consequent‐parallel reaction scheme was applied. A proportional increase of the maximal synergetic effect with increase of temperature has been established. A qualitative interpretation of the observation is pres

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430208

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe copolymerization of methacrylic acid and acrylic acid in toluene was investigated and the reactivity coefficientsr1andr2have been determined. With dioxane as the solvent, deviations from the Mayo‐Lewis equation were observed. The copolymerization was further carried out in presence of poly(ethylene glycol) and the reactivity coefficients for the template copolymerization in toluene and benzene were determined. A slight increase ofr1and decrease ofr2have been established. The results are discusse

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430209

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY

摘要:

AbstractThe temperature dependence of specific heat of poly(isobutene) degraded under the action of strong Lewis acids has been investigated. From the calculated thermodynamic parameters have been drawn conclusions on the structural conversions of the macromolecules in the process of catalytic degradation. By means of13C‐NMR the formation of branched macromolecules was shown. On the basis of the results a degradation mechanism for poly(isobutene) is suggeste

ISSN:0323-7648    

DOI:10.1002/actp.1992.010430210

出版商:Akademie Verlag GmbH    

年代:1992

数据来源: WILEY