Chemically induced phase separation in the preparation of porous epoxy monolith

Li, Jianhua; Du, Zongliang; Li, Hangquan; Zhang, Chen

doi:10.1002/polb.22095

Cited by 13 publications

(15 citation statements)

References 18 publications

(20 reference statements)

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“…1) for APOP at ambient temperature and at 70°C and also by larger sizes of particles formed at higher temperature. With respect to the low content of POPs, which is apparently below the critical volume fraction, the phase separation that gives rise to the structure of POP particles in epoxy matrix proceeds by nucleation and a growth mechanism 26, 27. Figure 1 shows further evidence of a significant increase in particle size with clay content found for nonreactive POP compared with APOP.…”

Section: Resultsmentioning

confidence: 87%

Effect of poly(oxyalkylene)amines on structure and properties of epoxide nanocomposites

Kelnar

Rotrekl

Kaprálková

et al. 2012

J of Applied Polymer Sci

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A shortcoming of most polymer nanocomposites is relatively low toughness. An effective method to eliminate this is the use of a suitable combination of polymeric impact modifiers with organoclay, which may impart synergistic effects on the mechanical behavior of both thermoplastic and thermoset matrix nanocomposites. This work focuses on the effect of various combinations of amine-terminated (APOP) and hydroxyl-terminated poly(oxypropylene) (POP) and layered silicates on the structure and mechanical behavior of epoxy nanocomposites. The combination of APOP and POP with 0.5À5% wt % of organoclay leads to some compositions that produce well balanced mechanical behavior of the epoxy nanocomposite. The higher toughening effectiveness of APOP/ montmorillonite (MMT) compared with that of POP/ MMT is a consequence of formation of blended domains consisting of clay tactoids and fine APOP inclusions. An increase in the dispersed particle size with clay content was observed to be a consequence of more significant clay-induced nucleation of phase separation at the expense of clay-induced accelerated curing. The best mechanical behavior was observed for materials using an adduct of APOP and MMT, which was obtained using the ion exchange of sodium ions of MMT by protonated APOP. The enhanced mechanical behavior was due to the formation of nanosized planar arrays by self-pilling of elastomer-modified clay and the corresponding increase in the T g of the epoxy. The structure/property relationships of these systems indicate that this type of clay polymer combination provides an effective way of modifying the mechanical behavior of epoxy nanocomposites.

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Section: Resultsmentioning

confidence: 87%

Effect of poly(oxyalkylene)amines on structure and properties of epoxide nanocomposites

Kelnar

Rotrekl

Kaprálková

et al. 2012

J of Applied Polymer Sci

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“…In contrast, there was a significant dependence of the particle size on the curing temperature, with an increase in size from ∼ 100 nm at 20°C to ∼ 300 nm at 80°C. This increase undoubtedly corresponds to phase separation via nucleation and growth mechanism expected for the low concentrations of the second phase polymer28–30 that we used. A similar increase in the particle size with increasing temperature has been reported for analogous epoxy systems by others 28, 31, 32.…”

Section: Resultsmentioning

confidence: 89%

Effect of amine‐terminated butadiene‐acrylonitrile/clay combinations on the structure and properties of epoxy nanocomposites

Kelnar

Rotrekl

Kaprálková

et al. 2012

J of Applied Polymer Sci

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The effect of the clay content and the method of its combination with amine-terminated butadiene-acrylonitrile (ATBN) on the structure and behavior of epoxy was studied. In the case of the simultaneous addition of both components, the increasing clay content had a very small effect on the size of the reaction-induced phase separationformed particles at 5% rubber content due to predominant elimination of two major clay effects, i.e., the nucleation due to phase separation and the kinetics. As a result, both the time window between the onset of phase separation and vitrification and the viscosity at the cloud point did not change significantly. The minor change in the particle size/clay con-tent dependences with different curing temperatures indicates that the balance between the two clay effects shifted. The corresponding study of the mechanical behavior indicated that the best balanced mechanical properties were obtained at certain clay/ATBN ratios, and thus, there was synergy between the components. Similar mechanical parameters were obtained for the application of both components in the form of ATBN/montmorillonite intercalate.

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“…8 In these cases, 1-decanol was poor solvent, and cyclohexanol acted as a good solvent for the polymer. Therefore, it usually needs tedious experiments to search for the designed structure of 3D bicontinous skeleton; Jianhua Li et al 18,19 have made a serious of research to regulate the polymer structures, and found that the average pore size increased with increasing porogen concentration, increasing curing temperature, and decreasing the content of curing agent. 9 These morphological changes mainly resulted from the difference between reaction and phase separation rates in various porogenic solvents.…”

Section: Introductionmentioning

confidence: 99%

Detailed exploration of structure formation of an epoxy-based monolith with three-dimensional bicontinuous structure

Zhou

et al. 2015

RSC Adv.

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To explore a clear formation mechanism of a three-dimensional (3D) bicontinuous skeleton and control the structure of an epoxy-based monolith, we have prepared the monolith using a mixture of good and poor solvents. The influences of reaction and phase separation parameters, such as molecular weights and content of porogenic poor solvents, porogenic good solvent concentration, equivalent ratio of epoxy group to amine and reaction temperature on the final morphology are systematically studied by monitoring the reaction process with differential scanning calorimetry (DSC) and observing the cloud points (CP). Depending on the above parameters, the resultant morphology can be varied ranging from closed pore structure to globules aggregated structure, which was controlled by the competitive kinetics between the domain coarsening and the structure freezing. The optimized monoliths with uniform and controllable pores have great potential for application in chromatographic separation, membrane filters, and membrane emulsification.

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Chemically induced phase separation in the preparation of porous epoxy monolith

Cited by 13 publications

References 18 publications

Effect of poly(oxyalkylene)amines on structure and properties of epoxide nanocomposites

Effect of poly(oxyalkylene)amines on structure and properties of epoxide nanocomposites

Effect of amine‐terminated butadiene‐acrylonitrile/clay combinations on the structure and properties of epoxy nanocomposites

Detailed exploration of structure formation of an epoxy-based monolith with three-dimensional bicontinuous structure

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