Reaction-induced phase separation in an epoxy/low molecular weight solvent system
Blends based on a stoichiometric mixture of diglycidyl ether of bisphenol A (DGEBA) and 2,2′-bis(4-amino-cyclohexyl)methane (ACHM) and cyclohexane as low molecular weight solvent were studied. The polymerization kinetics data experimentally obtained at different temperatures (30-60°C) were accurate...
| Autores: | , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2003 |
| País: | Argentina |
| Recursos: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/78257 |
| Acesso em linha: | http://hdl.handle.net/11336/78257 |
| Access Level: | acceso abierto |
| Palavra-chave: | Reaction Induced Phase Separation Epoxy Low Molecular Weight Solvent Cyclohexane Thermodynamic Analysis Kinetics Data Polymerization Rate Diglycidyl Ether https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 https://purl.org/becyt/ford/2.5 https://purl.org/becyt/ford/2 |
| Resumo: | Blends based on a stoichiometric mixture of diglycidyl ether of bisphenol A (DGEBA) and 2,2′-bis(4-amino-cyclohexyl)methane (ACHM) and cyclohexane as low molecular weight solvent were studied. The polymerization kinetics data experimentally obtained at different temperatures (30-60°C) were accurate fitted using a mechanistic model. The effect of the solvent over the polymerization rate was analyzed. No influence of the presence of the solvent was found up to 20 wt% of cyclohexane in the sample. The thermodynamic analysis using Flory-Huggins model allowed determination of the initial miscibility of binary blends containing DGEBA/cyclohexane and pseudo-binary mixtures of DGEBA/ACHM/cyclohexane. The presence of ACHM increases the DGEBA/cyclohexane initial solubility. The reaction-induced phase separation was described using a conversion-composition transformation phase diagram. It indicates that phase separation takes place by a nucleation and growth (NG) mechanism. The appropriate selection of composition of the blend and polymerization conditions led to final materials with a desired closed cell porous morphology. |
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