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Reaction and Morphology Development Influenced by Diffusion in a Thermoplastic/Thermoset Blend
Author(s) -
Bella Redha,
Cassagnau Philippe,
Fenouillot Françoise
Publication year - 2006
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200690029
Subject(s) - thermosetting polymer , diglycidyl ether , materials science , polystyrene , diffusion , epoxy , morphology (biology) , polymerization , chemical engineering , polymer chemistry , bisphenol a , thermoplastic , composite material , polymer , thermodynamics , physics , genetics , biology , engineering
Diglycidyl ether of bisphenol A (DGEBA) and 4,4′‐methylenebis [2,6‐diethylaniline] (MDEA) are miscible in polystyrene at 177 °C. We have studied how their diffusion rate in a molten polystyrene matrix influences their polymerization rate and the morphology of the thermoset particles formed at the end of the reaction. The global composition of the blend was 60 wt% of PS and 40 wt% of epoxy‐amine. The diffusional control of the reaction was evidenced by comparing the time of reaction of an initially homogeneous mixture with that of different bi‐layer samples. The reaction was controled by the diffusion for relatively thick layers (>0.3. mm). A gradient of morphology was obtained due to the diffusionnal control of the reaction. The asymetricity of this gradient may be explained by three factors: differences in diffusion coefficients, in thermodynamic interactions and in viscosity.