摘要:

AbstractBy analysing the polycondensation of ethylene glycol with dimethyl terephthalate, the influence of 1,4‐aminoanthraquinone dyestuffs on the chemical and molecular properties of dope dyed poly(ethylene terephthalate) has been determined. The results show that dope dyed poly(ethylene terephthalate) differs from the uncoloured polymer by a possession of a higher amount of ‐COOH end groups and diethylene glycol units. The shape and the position of molecular weight distribution curves determined by gel permeation chromatography are also influenced by the soluble dyestuffs u

ISSN:0007-1641    

DOI:10.1002/pi.4980140202

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThe design and evaluation of Friedel‐Crafts polymers as electrical insulants is discussed with particular reference to materials based on p‐xylylene glycol dimethyl ether and terphenyl. The general synthetic procedure for these applications normally consists of two idealised stages. The first involves the formation of a soluble, linear or branched polymer. The second consists of its conversion, sometimes after isolation and compounding operations, to a cross‐linked material at a controllable rate in a moulding or film‐forming reaction.A variety of catalysts and reaction conditions were examined, of which SnC14 and the so‐called ball clays (a range of kaolin‐based minerals varying in acidity and iron content) proved to be the most interesting. The structures of the polymers at various stages of the reaction leading to the final cross‐linked product are discussed together with the properties of the result

ISSN:0007-1641    

DOI:10.1002/pi.4980140203

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThe preparation and photo‐electrical properties of free standing water impermeable membranes of polyvinylcarbazole (PVCa) are described. The membranes, with aqueous electrolyte contacts, show ohmic photoconduction when doped with crystal violet (CV) and irradiated with light of wavelengths>475 nm. Optimum levels of doping, which approach one dye molecule per molecule of polymer, give photocurrent/dark current ratios of 106with light levels of 175 mW cm−2. On open circuit pH dependent photovoltages>200 mV are obtained which produce photovoltaic currents>10−10A cm−2under short circuit conditions.The influence of combinations of tetracyano‐o‐benzoquinone (TCOBQ) and CV is additive but, in contrast to reported findings at high voltage gradients, combinations of tetracyanoquinodimethane (TCNQ) and CV lower the efficiency of the photoconduction process by an order of magnitude. Action spectral studies relate this effect to a photoredox process at the electrolyte‐membrane interface associated with the absorption band at 410nm in TCNQ, and suggest domaines of TCNQ in the polymer.The role of the sensitiser in the transfer of electrons from the membrane to the electrolyte and across the membrane is discussed and the importance, for efficient electron transfer, of the spacial relationship between CV molecules and the stacked carbazole residues in the PVCa molecules

ISSN:0007-1641    

DOI:10.1002/pi.4980140204

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980140205

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980140201

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY