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Kramarenko, V. Yu.; Ezquerra, Tiberio A.; Calleja, F. J. Baltá; Privalko, V. P.

doi:10.1023/a:1004871413100

Cited by 5 publications

(2 citation statements)

References 18 publications

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“…Recently, it has been related to an increase of cooperativity with increasing cross-linking density. 22 The relaxation in this network is small and appears at temperatures well below the R relaxation. Thus, the relaxation shown is nearly a pure R relaxation.…”

Section: Resultsmentioning

confidence: 90%

Miscibility of Poly(butyl acrylate)−Poly(butyl methacrylate) Sequential Interpenetrating Polymer Networks

et al. 2001

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The aim of this work is to study by means of dielectric and dynamic-mechanical techniques the miscibility and molecular mobility of sequential interpenetrating polymer networks (IPNs). Sequential poly(butyl acrylate)/poly(butyl methacrylate) interpenetrating networks with different cross-linking densities were prepared using ethylene glycol dimethacrylate as cross-linking agent. Loosely cross-linked IPNs undergo phase separation, as detected by the occurrence of two clearly differentiated main dielectric and dynamic-mechanical relaxation processes corresponding to the two components. Forced compatibilization phenomenon appears in the highly cross-linked IPNs. The IPN cross-linked with 10% EGDMA shows a single main dynamic-mechanical relaxation process. Only the R main relaxation process appears in the PBA networks within the temperature range of the experiments conducted in this work. The dielectric relaxation spectrum of PBMA networks shows the well-known and R relaxation processes, which coalesce in a single R relaxation in the merging region. In the compatibilized IPNs, both the R and the relaxation shift toward lower temperatures as the amount of PBA segments in the IPN increases. The merging region shifts toward lower temperatures as well. In addition to these relaxation processes originated by the homogeneous mixture of PBA and PBMA segments, the IPNs containing more than 50% PBA also show the main PBA's dielectric relaxation process slightly shifted toward higher temperatures. This fact implies that an important part of the PBMA segments is mixed with PBA at the molecular level.

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Section: Resultsmentioning

confidence: 90%

Miscibility of Poly(butyl acrylate)−Poly(butyl methacrylate) Sequential Interpenetrating Polymer Networks

et al. 2001

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“…For polystyrene, both dynamic fragility and T g increase with increasing molecular weight [9,69,70], while for PDMS, the T g is only weakly affected by molecular weight, as is its fragility [71]. Studies of the effects of crosslink density on the segmental dynamics also show an increase in dynamic fragility with crosslink density [60,64,72,73]. Again fragility changes in the same direction as T g does.…”

Section: Dynamic Fragility and Apparent Activation Energy At T Gmentioning

confidence: 96%

Correlation between dynamic fragility and glass transition temperature for different classes of glass forming liquids

Qin

McKenna

2006

Journal of Non-Crystalline Solids

340

395

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Linear polyurethanes with imidazoquinazoline rings: preparation and properties evaluation

et al. 2019

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In this work, research concerning the synthesis and properties of linear polyurethanes (PUs) with the imidazoquinazoline rings was represented. Reaction conditions of 2,6-bis(2-hydroxyethyl)-1-phenylimida-zo[1,5-c]quinazoline-3,5-dione (BHPIQ) with 1,6-hexamethylene diisocyanate were determined and optimized. These conditions are adapted to reaction of BHPIQ with 4,4′-diphenylmethane diisocyanate and 2,4-toluene diisocyanate. New PUs with imidazoquinazoline rings were characterized by spectral methods (1 H-NMR and IR spectroscopies), which confirm their structures. Their molar masses and dispersity index were measured by size exclusion chromatography method. The wide-angle X-ray scattering and differential scanning calorimetry (DSC) studies have shown that all PUs based on BHPIQ are amorphous. Moreover, thermal properties of PUs were investigated by thermogravimetry analysis, standard DSC, and temperature-modulated DSC methods. During thermogravimetric measurements, the exhaust gases were analyzed by FTIR method. Incorporation of imidazoquinazoline ring into the PU chains escalates their glass transition temperature; thus, their heat resistance was enhanced. Furthermore, their degradation rate and the amount of released degradation products were

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Untitled

Cited by 5 publications

References 18 publications

Miscibility of Poly(butyl acrylate)−Poly(butyl methacrylate) Sequential Interpenetrating Polymer Networks

Miscibility of Poly(butyl acrylate)−Poly(butyl methacrylate) Sequential Interpenetrating Polymer Networks

Correlation between dynamic fragility and glass transition temperature for different classes of glass forming liquids

Linear polyurethanes with imidazoquinazoline rings: preparation and properties evaluation

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