ISSN:1042-7147    

DOI:10.1002/pat.1990.220010301

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractAlkali‐metal salts of (ω‐carboxy)oligo(oxyethylene) methacrylate (CME12M, M = Li or Cs) have been synthesized and polymerized to prepare solid polymer electrolytes. These types of solid polymer electgrolytes provide a homogeneous phase, since these polymers have a flexible main chain, an oligo(oxyethylene) side chain for ion conduction, and a carrier ion source in one repeating unit. The AC conductivity of P(CME12Li) homopolymer is 8.9 × 10−9S cm−1at 30°C, while that of P(CME12Cs) is 3.3 × 10−6S cm−1at 30°C, which is the highest value among single ion conductors, have been reported as polyelectrolyte “homopolymer” without any additives. High ionic conduction of P(CME12Cs) is due to low glass transition temperature (Tg= −54°C) and weaker ion–ion and ion–dipole interac

ISSN:1042-7147    

DOI:10.1002/pat.1990.220010302

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

Abstract1,3‐Cyclohexadiene is electropolymerized at a lower applied potential, compared with the polymerization of other alkene compounds, to give insoluble polymer film on an electrode. The formed polymer contains a phenylene repeated unit, which is confirmed by IR,1H‐ and13C‐NMR spectroscopy. Poly(cyclohexene) produced by the electropolymerization is partially aromatized by the oxidation to form a phenylene unit which is accompanied by an elimination of a p

ISSN:1042-7147    

DOI:10.1002/pat.1990.220010303

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe vitrification effect during the curing reaction of amine terminated butadiene acrylonitrile copolymer‐(ATBN)‐modified epoxy resin is studied by the differential scanning calorimetry. A new reaction kinetic equation is derived to describe the effect of vitrification on the reaction rate at both glassy and rubbery state of reactants. ATBN is added to improve the impact properties of the cured epoxy resin. The phase separation behavior during the curing reaction is analyzed by the light scattering and turbidity experiments. From the results of the cloud point measurements, it is observed that the ATBN‐epoxy system showed upper critical solution temperature (UCST) behavior. From the results of the light scattering experiments, the domain correlation length increases as the content of ATBN incr

ISSN:1042-7147    

DOI:10.1002/pat.1990.220010304

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractPhase separation behavior of the chemical blending of the polybutadiene (PBD)/polystyrene (PS) was investigated by the light scattering technique. Polybutadiene was dissolved in the styrene monomer and the polymerization of the styrene monomer was carried out thermally in the presence of the dissolved polybutadiene. The effect of the PBD composition, synthesis temperature and the PS crosslink density on the phase separtion behavior were analyzed. The mixture of PBD/PS/styrene monomer showed UCST (upper critical solution temperature) character. It was found that the phase separation was proceeded by the nucleation and growth mechanism in the early stage of polymerization. The time (t) dependence of the domain correlation length (dm) could be represented by a power law in the late stage of the phase separation. The crosslinking of PS hindered phase separation in the coalescence process.

ISSN:1042-7147    

DOI:10.1002/pat.1990.220010305

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractPoly(methacrylic acid) containing 0.4 mol% of anthryl groups (PMA‐A) was prepared and its formation of polyelectrolyte complex (PEC) with some polycations in aqueous solution was investigated. The fluorescence intensity of the anthracene (Anth) chromophore increases with the formation of PEC, which may be caused by enhanced hydrophobicity of the microenvironment around the Anth moiety. The intensity depends strongly on the chemical structures and properties of polycations (integral or pendant type, flexibility and hydrophobicity of polymer chains, etc.) and on the experimental conditions (pH and ionic strength

ISSN:1042-7147    

DOI:10.1002/pat.1990.220010306

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe gas (oxygen and nitrogen) transport characteristics of the IPN membranes of polyurethane/polysturene were studied. The effect of synthesis temperature, composition, and crosslink density of the IPN membranes were analyzed. Polyurethane was prepared thermally and polystyrene was prepared by photolytic polymerization methods at various temperatures. The degree of intermixing between component polymers in the IPN membrane increased with decreasing synthesis temperature from 50°C to −10°C. The PS phase Tg was shifted inwardly up to 12°C. The permeability coefficient decreased and ideal separation factor increased also with decreasing the synthesis temperature due to the increase of miscibility. The permeability coefficient of oxygen and nitrogen ranged in the 10−10and 10−10order of magnitude. The permeability coefficient showed the minimum value and the ideal separation factor showed the maximum value at about 40 wt% polyrethane composition. The permeability data agreed well with the simple free volume model proposed by

ISSN:1042-7147    

DOI:10.1002/pat.1990.220010307

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractPolymethylsiloxane graft‐crosslinked with oligo(ethylene oxide) (EO) was synthesized and characterized. The polymer was an elastic solid and stable to hydrolysis. Polymer/salt complexes were formed on mixing with lithium trifluoromethane‐sulfonate(LiCF3SO3). The ionic conductivity of the complexes was measured by complex impedance method and the conductivity reached 6 × 10−5S cm−1at 25°C and 1.5 × 10−4S cm−1at 40°C. The effect of salt concentration, crosslinking, length of EO units and moisture content on the conductivity were investigated. Glass transition temperature and thermal stability of the polymer and the polymer/salt complexes were determined by differential scanning calorimeter and thermogravimetric analys

ISSN:1042-7147    

DOI:10.1002/pat.1990.220010308

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractStable patterns with high local electrical conductivities and different local spin densities can be created in ladder type polymer films (5–20 μm thickness) by first preheating to a temperature (Tp) followed by spatically selective laser annealing. Two dimensional images of the spin distribution in such films were determined using ESR imaging. The 2‐D images of 20 μm films exhibit peaks or dips in the spin density at the laser illuminated regions, which strongly depend on the preheating conditions. These phenomena are attributed to spin density gradients caused by a temperature gradient across the film upon illumination; it should be noted that the laser beam does not penetrate completely through such relatively thick

ISSN:1042-7147    

DOI:10.1002/pat.1990.220010309

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractInterest in the recently reported polyimide resins containing disulfide bonds, which could be cleaved by reduction for reprocessing and/or recovery, prompted the present investigation of polymers and copolymers of the DTDA bismaleimide previously described. Differential scanning calorimetry (DSC) studies were carried out to identify the structures, curing conditions and modifications of reduced products of potential value for industrial applications. Results have shown that selected cured copolymers of DTDA bismaleimide with aromatic diamines can be solubilized by reduction and reset in subsequent reactions to yield thermosets of satisfactory properties.

ISSN:1042-7147    

DOI:10.1002/pat.1990.220010310

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY