摘要:

AbstractThe reaction of cyclic dicarboxylic anhydrides (3) with prepolymers2(from aniline and 2,2‐bis[4‐(2,3‐epoxypropoxy)phenyl]propane (1)) results in new modified prepolymers4–6containing carboxylic groups and reactive glycidyl end groups. The structure of4–6was determined by IR,1H NMR,13C NMR spectroscopy, elemental analyses andM̄n(by v. p.o.) values. By simple heating to 100–140°C prepolymers4–6were crosslinked to hybrid networks (7). Their structure was studied by IR and solid‐state13C

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901101

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractPolymerizations of higherα‐olefins (C10–C20) were carried out at 40°C in heptane, using the following three catalysts which differ in the isospecificity for propene polymerization: Solvay type TiCl3/Cp2TiMe2((A) highly isospecific), Solvay type TiCl3/AlEt3((B) isospecific) and TiCl3.3Py/MgCl2/AlEt3((C) aspecific). The isospecificity of the catalysts was found to decrease in the following order: (A) ≫ (B) ≫ (C), which agrees well with the results obtained in propene polymerization. The crystallinity of these polymers is discussed

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901102

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractChemically and thermally stable thin films of polyphthalocyanine were prepared by a simple evaporation‐polymerization method. The rectifying characteristics of metal/semiconductor/metal (MSM) type sandwich devices with the film were studied. A Schottky type device metal (Cu, Al, Ti)/polyphthalocyanine/Cu shows reproducible rectifying characteristics when Ti is selected as a counter electrode. The reproducibility is improved by pre‐oxidation treatment of the surface of Cu substrate. Best electric parameters for the device are as follows: rectifying ratio = 14; threshold potential difference = 0,61 V; saturation current = 2,5 · 10−6A · cm−2; barrier height = 0,75 eV; diode ideality parameter = 4,23. Doping of five kinds of quinones [p‐benzoquinone (p‐BQ), tetrabromo‐p‐benzoquinone (p‐TBBQ) tetrachloro‐p‐benzoquinone (p‐TCBQ) tetrachloro‐o‐benzoquinone (o‐TCBQ) 2,3‐dichloro‐5,6‐dicyanobenzoquinone (DDQ)] and 2,5‐cyclohexadien‐1,4‐diylidenedimalodinitrile (TNCR) in thin films of polyphthalocyanine affected electrocharacteristics in some cases. The diode ideality parameter decreases to 2,17 at 0,90 · 10−6mol · cm−1of p‐TBBQ, and the rectifying ratio increases to about fourteen times by doping p‐TBBQ and p‐TCBQ. T

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901103

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractA molecular imprinting procedure based on electrostatic and hydrogen bonding interactions was developed, resulting in polymers of high selectivity for complexing ofL‐phenylalanine anilide. The polymerization conditions were chosen in such a way that the formation of solution complexes between methacrylic acid (MAA) and the template (L‐phenylalanine anilide) prior to polymerization would be favored. Thus, by increasing the ratio of MAA to the crosslinker (ethylene dimethacrylate, EDMA), polymers of a higher enantioselectivity and binding capacity were obtained. In the chromatographic mode, a high chiral separation factor (a= 3,4) was observed even for polymers prepared in presence of nearly 50 mol‐% MAA in the monomer mixture. However, the use of polymers prepared by initiating at a lower temperature (40 instead of 60°C) and polymers prepared using porogens of lower polarity (benzene instead of acetonitrile) only resulted in higher capacity factors (K'). The association constant for the binding ofL‐phenylalanine anilide to the sites of an imprinted polymer as well as the number of accessible sites of the latter were estimated from a binding study using a batch and a chromatographic p

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901104

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractGroup transfer polymerization of methyl methacrylate (MMA) in tetrahydrofuran with (1‐methoxy‐2‐methyl‐1‐propenyloxy)trimethylsilane (1) as initiator and tetrabutylammonium cyanide as catalyst was investigated. Beside a fast isomerization, only very slow dimerization reactions of the initiator in the presence of the catalyst were observed. Therefore, the system was found to behave like a living one. Values ofM̄wM̄napproached 1,3 at low catalyst concentrations. Tacticity measurements yielded about 60% syndiotactic, 36% heterotactic and 3% isotactic triads. Induction periods in time‐conversion curves obtained with1as initiator and intercepts in the plots of the number‐average molecular weight (M̄n) vs. monomer conversion vanished, when the reaction was initiated with the first addition product of1and MMA. This is assumed to be a strong indication, that in the investigated system a slow initiation step between1and the first MMA unit precedes the prop

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901105

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractGroup transfer polymerization (GTP) of methyl acrylate (MA) with 1‐methoxy‐1‐propenyloxytrimethylsilane (MTP) as initiator and tetrabutylammonium fluoride trihydrate and tetrabutylammonium cyanide as catalysts in tetrahydrofuran was investigated. Tetrabutylammonium fluoride trihydrate turned out to be absolutely unsuited as GTP catalyst, since its crystal water destroys the initiator and the active centres. Furthermore, in side reactions between the initiator and the catalyst, the concentrations of both are diminished. Tetrabutylammonium cyanide is a powerful catalyst of GTP of MA, leading to complete conversion of the monomer, but initiates an anionic polymerization of MA too, which, however, is of minor importance in the main part of the reaction. Reaction rates may easily be controlled by the catalyst concentration. Number‐average molecular weights are dependent on initiator concentration. They are lower as well as higher than those expected for a really living system, pointing to a rather complicated overall r

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901106

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractAsymmetrically substituted, liquid‐crystalline phthalocyanines were synthesized. They contain one methoxy, six dodecyloxy and one acryloyloxy‐ or methacryloyloxydodecyloxy groups. The latter functions were polymerized under free radical conditions to give polymers with molecular weights between 9000 and 47000. The aggregation behaviour of the phthalocyanines in the polymer side chains was studied in solution by absorption and fluorescence spectroscopy. An enhanced intramolecular interaction between the phthalocyanines was observed. In the solid state this interaction is reflected in the spontaneous formation of a columnar structure. The polymers, however, do not display liquid‐crystalline behaviour. Temperature‐dependent luminescence measurements (at 4,2 – 300 K) were performed and the results are explained by the presence of an efficient energy migration process through the stacked phthalocyan

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901107

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractIn order to solve the problem of polymer swelling, which limits the resolution for negative resists, new resists were developed which show no swelling. The undesirable swelling can be suppressed by converting nonpolar crosslinked polymers into polar ones, which are soluble after irradiation. This aim was attained by mixing a polystyrene bearing tetrathiafulvalenyl (TTF) groups with 1,2‐dibromo‐1,1,2,2‐tetrachloroethane. For our study, we applied resists including poly(4‐chloromethylstyrene)s containing tetrathiafulvalenecarbonyloxymethyl groups (1and2). Poly(4‐chloromethylstyrene)s (4) or poly[styrene‐co‐(4‐chloromethyl)styrene]s (5) with a variety of controlled molecular weights and molecular weight distributions were prepared by radical chain polymerization. The reaction of cesium tetrathiafulvalenecarboxylate (3) with4or5was carried out and the resultant substituted polymers1and2wer

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901108

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractIn order to study the influence of the nature of the moiety bearing a tetrathiafulvalenyl group in the polymers upon the microlithographic properties of resists, poly(p‐chloromethylstyrene)s and poly(styrene‐co‐p‐chloromethylstyrene)s containing the 4‐tetrathiafulvalenylphenoxymethyl group with a variety of controlled molecular weights and molecular weight distributions were studied. The copolymers were all prepared by reaction of poly(4‐vinylbenzyl chloride) with potassium 4‐tetrathiafulvalenylphenolate (3). Without exception, the resulting poly[p‐chloromethylstyrene‐co‐p‐(tetrathiafulvalenylphenoxymethyl)styrene]s are highly insoluble. However, by reaction of potassium 4‐tetrathiafulvalenylphenolate with poly(styrene‐co‐p‐chloromethylstyrene) soluble

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901109

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractThe complex [η3‐methylallyl(η4‐cycloocta‐1,5‐diene)nickel] hexafluorophosphate (2) was found to be an efficient catalyst for the oligomerization of styrene without using a Lewis acid. Oligomers and polymers with low degree of polymerization were obtained and characterized by GPC and NMR spectroscopy. Solvents and ligands have a strong effect on the catalyst activity, the molecular weight distributions and the polymer microstructure. The end groups were characterized in the case of the ligand‐free and the tributylphosphine and tricyclohexylphosphine‐modified systems. A terminal benzylidene group was observed except for the latter basic and bulky phosphine which led to a methylene terminal group. A mechanism involving a hydridonickel specie

ISSN:0025-116X    

DOI:10.1002/macp.1989.021901110

出版商:Hüthig&Wepf Verlag    

年代:1989

数据来源: WILEY