摘要:

AbstractRacemic and chiral [(4‐cyano‐4′‐biphenyl)oxy] and [(4‐methoxy‐4′‐biphenyl)oxy]methyloxiranes were prepared from racemic epichlorohydrin or racemic and chiral glycidols and polymerized in dimethylsulfoxide (DMSO) with ButOK as the initiator system. Initial phase identifications were made by differential scanning calorimetry (DSC) and optical microscopy techniques and confirmed by X‐ray diffraction measurements. Upon heating, all the monomers show only a crystal–isotropic phase transition. The racemic and chiral [(4‐cyano‐4′‐biphenyl)oxy]methyloxiranes exhibit a nematic and a cholesteric monotropic phase, respectively. Methoxybiphenyl substituted polyethers are crystalline and insoluble in virtually all common solvents. Cyanobiphenyl substituted polyethers are soluble under the same experimental conditions and show enantiotropic liquid crystalline properties. The racemic polymer exhibits a nematic phase, while the optically active polyme

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050401

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractPoly(2,5‐dimethylphenylene sulfide) was prepared by oxidative polymerization of sulfur chloride with p‐xylene using 2,3‐dichloro‐5,6‐dicyano‐p‐benzoquinone (DDQ) as an oxidizing agent. The reaction proceeded efficiently under atmospheric pressure and at room temperature. The polymer formed had a high melting temperature and linear structure which was confirmed by spectroscopies. The effects of reaction time, solvent, temperature and oxidizing agent on polymerization are a

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050402

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractCrosslinked poly(N‐isopropylacrylamide) gel was tested on the feasibility for a preparative electrophoretic matrix. Horse heart myoglobin and bovine hemoglobin were well separated on the gel matrix electrophoretically by molecular sieving effect of the gel network. Relative mobilities of those proteins in the gel were larger than those in a crosslinked polyacrylamide gel of the same polymer concentration. After the separation, the protein‐containing portion of the gel underwent swelling at 4°C and deswelling at 37°C, alternatively. As a result of the deswelling, each protein was recovered in a discharged solution out of the gel at almost 100%

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050403

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractFive different polyaniline salts have been prepared by chemical polymerization of aniline in aqueous solution of different acids. The polyaniline base was obtained from the corresponding polyaniline salt by dedoping using aqueous ammonium hydroxide solution. Electron paramagnetic, electronic absorption, infrared spectral and conductivity measurements have been performed on the polyaniline salts and polyaniline bases. This composition and the extent of dopant in polyaniline salt systems have been determined. There is no definite correlation between the conductivity and the stoichiometric ratio between the polyaniline base and the acid, and also the spin concentration.

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050404

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractIt is well known that, with respect to the director, nematic elastomers can be macroscopically aligned by uniaxial mechanical fields. Extending this method to a chiral smectic C elastomer, depending on the experimental set‐up either smectic layer orientation or director orientation parallel to the stress axis occurs. In order to align the director and the smectic layers a biaxial mechanical field (e.g. shear field) consistent with the phase symmetry has to be used to achieve a macroscopically uniform orientation of the untwisted smectic C*structur

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050405

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractIt is shown, for the first time, that single‐component continuous networks of a low molecular weight electron acceptor additive can be grown in a polymer matrix. Such networks can be doped using, e.g., iodine vapor and converted into conductive CT complexes without losing continuity, thereby making the polymer film conductive. Polyethylene films with tetrathiotetracene networks are obtained, and their doping with iodine vapor in air is investigated by means of conductivity and spectrophotometry in the visible range. It is concluded that doping of the surface layer of the microcrystallites is sufficient to observe a significant increase in the film conductivity, which makes possible the use of such systems as sensor

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050406

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractTransparent photochromic inorganic/organic hybrid gels involving the Chemically bonded spirobenzopyran moiety have been prepared by the sol–gel reactions using tetraethoxysilane, the silanol‐terminated oligomeric poly(dimethylsiloxane), and spirobenzopyrans with the alcoxysilyl gro

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050407

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050408

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

ISSN:1042-7147    

DOI:10.1002/pat.1994.220050409

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY