摘要:

AbstractHeteroaggregations of the pair of cyanine dyes pinacyanol and thiacarbocyanine induced by the polyanions poly(potassium styrenesulfonate) and poly(potassium vinyl sulfate), and of methylene blue and acridine orange induced by mercuric chloride are described. In each case the characteristic of heteroaggregation, namely the enhancement of the metachromatic band of the partner dye having λmaxat relatively shorter wavelength at the expense of the absorbance at the metachromatic band of the other dye, is reflected in the difference spectra. The dependence of the shape of the metachromatic band of pinacyanol on the nature of the polyanion inducing metachromasia is also reflected in the heteroaggregation of this dye and thiacarbocyanine induced by the two different polyanions. Mercuric chloride, though not a polyanion, also induces strong heteroaggregation of methylene blue and acridine orange

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830121

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe crystal unit cell of a series of normal diamides, RNHCO(CH2)2nCONHR (1) with RCH3(CH2)5 andnvarying from 0 up to 4, has been determined from X‐ray diffraction patterns of oriented films. This work forms part of the study to investigate the relation between microstructure and physical properties, in particular diamagnetism. The unit cell is tricline for all members of the series having one chain molecule per unit cell. The structure of normal diamides consists of extended chains tilted 75° from the sheet edge allowing hydrogen‐bond formation within the sheet. The long spacings obtained have been associated to oblique structures of hydrogen‐bonded sheets, except for the diamide withn= 1. A. shear between adjacent hydrogen‐bonded sheets of 3 repeating chain units offers the most probable explanation for the structure

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830122

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe extrapolated melting point of native 1,4‐trans‐isotactic‐polypentadiene obtained by inclusion polymerization in pre‐irradiated perhydrotriphenylene is 104°C, 10 K higher than that of a long‐annealed conventional polymer. The WAXS spectrum corresponds to that of the already known paracrystalline structure; this notwithstanding, its heat of melting is 20–70% higher than that of polypentadiene crystallized from solution or from the melt. The native polymer shows noteworthy superheating phenomena and is not able to induce crystallization of high‐melting crystals from the melt. This behaviour is consistent with that predicted for extended‐chain polymeric crystals. This conclusion is supported by the absence of definite peaks in the SAXS spectrum of th

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830123

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractSemi‐interpenetrating polymer networks based on polystyrene and polystyrene‐polyisoprene three‐block copolymers (SIS) were prepared by anionic polymerization. Factors affecting synthesis, such as composition, molecular weight of either the unattached SIS or the polystyrene between crosslinks, elastomer content, have been varied. Their effect on network formation was examined by extraction experiments and swelling measurements. Their morphology was investigated by means of electron micro

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830124

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY