Investigation of the Microphase Separation in Blends of Polyurethane-Based Ionomers

Tsonos, Christos; Apekis, L.; Viras, Kyriakos; Stepanenko, L.V.; Karabanova, L. V.; Sergeeva, L. M.

doi:10.1081/mb-100100378

Cited by 23 publications

(23 citation statements)

References 31 publications

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“…As the tempera ture increases, the peak and the step shift to higher tem perature. 10 As can be seen from Fig. 1, for NP sol, the right wings of the curves have steps that shift to higher temperature.…”

Section: Resultsmentioning

confidence: 84%

Dielectric properties of sols of silver nanoparticles capped by alkyl carboxylate ligands

et al. 2011

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Sols of silver nanoparticles in toluene were studied by broadband dielectric spectroscopy (10 -3 -10 5 Hz). The frequency dependences of the specific alternating current (ac) conductiv ity and the complex electric modulus were used to estimate the temperature/frequency inter vals of long and short range charge transfer occurs, respectively. A considerable increase (by more than 30°С) in the Vogel temperature T 0 and the glass transition temperature T g in sols compared with the pure solvent was found. It can be hypothesized that these cooperative effects reflect the initial stage of the superlattice formation. Although the dielectric characteristics of sols are generally controlled by the conductivity relaxation, the dielectric response was ob served in the high frequency range (1-10 3 Hz) at low temperatures (from -50 to +10°С). This response results from the presence of nanoparticles in solution. It is supposed that the relaxation is caused by the motion of ion impurities on the Ag nanoparticle surface within the carboxylate ligands shell. The dielectric properties of films strongly depend on both the characteristics of nanoparticles and the conditions of the film preparation. Like in sols, the direct current (dc) conductivity and the dielectric response of Ag nanoparticles in films are due to ion impurities.Key words: sols of silver nanoparticles, broadband dielectric spectroscopy, chemical sensors.As noted previously, 1 an important problem of the modern nanoindustry is the manufacture of stable mono disperse nanoparticles (NP) able to spontaneously form ordered 2D and 3D structures, so called superlattices, upon concentration. 2 From this standpoint, silver NP are of considerable interest as they combine valuable optical, catalytic, and other properties and are readily accessible. 3 The currently known methods for the synthesis of silver NP 4 mainly imply the use of multicomponent dilute sys tems at silver ion concentrations of 10 -3 -10 -4 mol L -1 , which hampers isolation of reasonable amounts of NP from the final sol. Therefore, particular attention is at tracted by the synthesis of silver NP by reducing silver carboxylates based on fatty acids with tertiary alklylamines first described by Yamamoto et al. 5 Characteristic features of the synthesis of silver NP from various low molecular weight carboxylates in triethylamine and their effect on the characteristics of the obtained NP were studied. 1 We made an attempt to investigate the initial stages of the self assembly of NP in a sol. ExperimentalThe synthesis and characteristics of samples have been de scribed in detail previously. 1 Silver carboxylate based on saturat ed tetradecanoic acid CH 3 (СН 2 ) 12 СООН was prepared by the reaction of the sodium salt of the acid with AgNO 3 in water. The carboxylate was reduced with triethylamine, which acted simul taneously as the reducing agent and as the reaction medium, at Т = 348 К under argon. The resulting silver NP had a rather narrow size distribution and an average radius of 1 nm and were coated with ...

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Section: Resultsmentioning

confidence: 84%

Dielectric properties of sols of silver nanoparticles capped by alkyl carboxylate ligands

et al. 2011

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“…Dielectric TSDC measurements [225] of the blends have shown four relaxation mechanisms. The subglass secondary γ relaxation (at ∼ 120 K) is associated with local motions of parts of the molecular chain.…”

Section: Properties Of Thermoplastic Apparent Ipnsmentioning

confidence: 99%

“…Polymer blends containing 5, 10, 30, and 50 mass % of PU 1 were obtained and studied. The details of preparation conditions are described in [224,225]. The molecular mobility, microphase morphology, and their dependence on the composition of the blends were investigated by TSDC, DSC, FTIR, SAXS, and other techniques.…”

Section: Properties Of Thermoplastic Apparent Ipnsmentioning

confidence: 99%

“…Thermoplastic AIPNs based on anion-containing PU 1 and polyaminourethane (PU 2 ) were prepared and investigated using different techniques by Stepanenko et al [224] and Tsonos et al [225,226]. The PU 1 was based on oligotetramethylene glycol (OTMG, MM 1000), TDI (mixture of 2,4-and 2,6-isomers in the ratio 65 : 35), and the magnesium salt of p-hydroxybenzoic acid (Mg-HBA); the molar proportion of the reagents was 1 : 2 : 2.…”

Section: Properties Of Thermoplastic Apparent Ipnsmentioning

confidence: 99%

“…The temperature at which α and MWS relaxations (T g and T MWS , respectively) appear in the TSDC plots and the magnitude of these relaxations are affected strongly by the degree of microphase segregation of the PU 1 and PU 2 in the blends. Based on TSDC measurements, a parameter m TSDC , a criterion expressing the relative degree of phase mixing, was introduced [225]. This parameter takes into account all the factors affecting phase mixing that the partial parameters express.…”

Section: Properties Of Thermoplastic Apparent Ipnsmentioning

confidence: 99%

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The chemical oxidation of aniline to form polyaniline (PANI) films and powder samples was made using Fenton reagent as an oxidizing agent in aqueous sulfuric acid medium. The PANI films were monitored by using the quartz crystal microbalance and the electronic absorption techniques. The optimum concentration was determined and the results were justified by measuring the UV-vis absorption spectra for the in situ PANI films. The conductivity for the PANI films and powder samples, prepared in different conditions, was measured. Also, the IR spectra, X-ray and the thermogravimetric analysis for the PANI powder formed in the bulk were measured and compared with the polymer prepared using ammonium peroxydisulfate. A preliminary investigation to the dielectric properties of the polymer powder was measured and discussed.

show abstract

Investigation of the Microphase Separation in Blends of Polyurethane-Based Ionomers

Cited by 23 publications

References 31 publications

Dielectric properties of sols of silver nanoparticles capped by alkyl carboxylate ligands

Dielectric properties of sols of silver nanoparticles capped by alkyl carboxylate ligands

Phase-Separated Interpenetrating Polymer Networks

Synthesis and characterization of polyaniline films using Fenton reagent

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