Morphologic and kinetic study of an epoxy-poly(ethyleneoxide) system. The fluorescence to predict miscibility

González‐Benito, J.; Esteban, Irène

doi:10.1007/s00396-004-1186-0

Cited by 15 publications

(4 citation statements)

References 37 publications

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“…With PSF content increasing, viscosity of the whole system was increased, and the actual reaction rate decreased more. A similar observation was also obtained by other authors, and physical reasons such as dilution effect and/or viscosity increase were mainly considered. − Dilution was a static average effect, while the viscoelasticity affected dynamic transport. In this system, these two effects showed the same tendency of depressing the chemical reaction.…”

Section: Resultssupporting

confidence: 84%

Dynamically Asymmetric Phase Separation and Morphological Structure Formation in the Epoxy/Polysulfone Blends

et al. 2011

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A thermoplastic polysulfone was used to blend with epoxy resin, and both the curing reaction and phase separation of the epoxy/polysulfone blend were investigated. Polysulfone did not alter the mechanism of curing reaction; however, it did depress the reaction rate. The details of the dynamically asymmetric phase separation, which was caused by the large differences in viscoelastic properties between epoxy and polysulfone component, were observed and studied. During the structure evolution, volume-shrinking behavior of the dynamically slow polysulfone component always existed even at fairly low (but still above the entanglement concentration) concentrations. More interestingly, when the curing temperature was higher than the glass transition temperature of polysulfone, volume shrinking with the consequence of layered structure formation was also observed as long as the viscoelastic asymmetry was maintained. These results indicated the generality of the mechanism of the dynamically asymmetric phase separation in this type of reactive system. Also, the influence of curing temperature was studied, and it was found that phase separation was promoted more than the curing reaction as the temperature was increased.

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Section: Resultssupporting

confidence: 84%

Dynamically Asymmetric Phase Separation and Morphological Structure Formation in the Epoxy/Polysulfone Blends

et al. 2011

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“…Furthermore, to optimize the conditions of curing for thermosetting materials, to monitor simultaneously, nondestructively, and in situ, both the chemical conversion and changes in T g or any other parameter directly related to it would be very helpful. Although several techniques have been used to monitor the curing process in epoxy‐based materials, Fourier transform infrared (FTIR) spectroscopy20–25 and differential scanning calorimetry (DSC)26–30 have probably been the most widely used. However, none of these studies have achieved the objective of nondestructively monitoring the curing process and determining in every moment either the value of the T g of the system or any parameter directly related to it.…”

Section: Introductionmentioning

confidence: 99%

Phase‐separation process in a poly(methyl methacrylate)‐modified epoxy system: A novel approach to understanding the effect of the curing temperature on the final morphology

Olmos

Loayza

González‐Benito

2010

J of Applied Polymer Sci

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In this study, the physical and chemical changes of a poly(methyl methacrylate) (PMMA)-modified epoxy system were examined to understand the effect of the curing conditions on its final morphology. The curing process of the PMMA-epoxy reactive system was complementarily analyzed by Fourier transform infrared spectroscopy in the near range (FT-NIR) and fluorescence spectroscopy. The relationships among (1) the chemical conversion of the curing reaction, (2) the first moment of the fluorescence emission band (hmi) arising from a chromophore chemically bonded to the epoxy reactive system, (3) the phase-separation process, and (4) the dynamics of the epoxy thermoset during its curing process are discussed. From a chemical point of view, FT-NIR did not reveal any significant change in the curing reaction with the presence of 2 wt % PMMA. However, in terms of physical changes, the analysis of the fluorescence response clearly showed variations in the curing reaction due to the presence of the thermoplastic polymer. Also, fluorescence allowed the estimation of the glass-transition temperature of the system with curing when the reaction was diffusioncontrolled, whereas Fourier transform infrared spectroscopy was not sensible enough. In the second part of this study, scanning electron microscopy images of the PMMAmodified epoxy system were analyzed to understand the effect of the temperature on the final morphology when the amount of thermoplastic was below the critical volume fraction. A linear dependence between the inverse of the mean area of the thermoplastic-rich domains and the inverse of the absolute temperature was obtained.

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“…The miscibility of cured PEO‐modified epoxy systems mainly depends on the applied cure cycle, content of PEO and hardener. Though phase separation can be observed mainly below the melting point of PEO in epoxy systems cured with some hardeners,30 previous studies5, 18 showed that DGEBA/DDM epoxy system modified with PEO studied in this work remains miscible due to interactions between the ether group of PEO and the hydroxyl group of DGEBA/DDM. However, DGEBA/DDM/PPO‐modified systems are microphase‐separated.…”

Section: Resultsmentioning

confidence: 60%

Highly Water‐Soluble, Fluorescent, Conjugated Fluorene‐Based Glycopolymers with Poly(ethylene glycol)‐Tethered Spacers for Sensitive Detection of Escherichia coli

Xue

Velayudham

Johnson

et al. 2009

Chemistry A European J

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Two bromide-bearing, fluorene-based, conjugated polymers with oligo(ethylene glycol)- and poly(ethylene glycol)-tethered spacers have been prepared by the Suzuki coupling polymerization of bromide-bearing, fluorene monomers. beta-Glucose and alpha-mannose residues have been covalently attached to the conjugated polymers by post-polymerization functionalization of the precursor polymers with thiol-functionalized carbohydrates under basic conditions through thioether linkage. A glucose-bearing glycopolymer with oligo(ethylene glycol)-tethered spacers (polymer A) displays poor water solubility. However, glycopolymers with poly(ethylene glycol)-tethered spacers (polymers B and C) are highly water-soluble due to their long, flexible, hydrophilic spacers. Incubation of the ORN178 strain of Escherichia coli (E. coli) with alpha-mannose-bearing glycopolymer (polymer C) results in the formation of fluorescent cell clusters, causing significant red shifts in UV/Vis absorption and fluorescent spectra of the polymer through multivalent cooperative interactions of the polymeric carbohydrates with the bacterial pili. In contrast, polymer C displays no interactions with a mutant ORN208 strain of E. coli.

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Morphologic and kinetic study of an epoxy-poly(ethyleneoxide) system. The fluorescence to predict miscibility

Cited by 15 publications

References 37 publications

Dynamically Asymmetric Phase Separation and Morphological Structure Formation in the Epoxy/Polysulfone Blends

Dynamically Asymmetric Phase Separation and Morphological Structure Formation in the Epoxy/Polysulfone Blends

Phase‐separation process in a poly(methyl methacrylate)‐modified epoxy system: A novel approach to understanding the effect of the curing temperature on the final morphology

Highly Water‐Soluble, Fluorescent, Conjugated Fluorene‐Based Glycopolymers with Poly(ethylene glycol)‐Tethered Spacers for Sensitive Detection of Escherichia coli

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