Journal of Applied Polymer Science · 1981 · 58 citations · 9 references
Natural SciencesMaterials EngineeringMaterials SciencePolymer ChemistryPolymer EngineeringPolymer MaterialsGelsPhase SeparationPolymer BlendsPolymer CharacterizationPolymer PhysicsPolymer StructureCloud PointCopolymers Phase BehaviorGel PointMiscibilityPolymer Blend Phase SeparationPolymer GelationPolymer Phase SeparationViscosity
Abstract The compatibility and phase separation behavior of mixtures of the diglycidyl ether of bisphenol A and carboxyl‐terminated butadiene‐acrylonitrile copolymers were studied by means of light transmission, viscosity measurements, and optical microscopy. Cloud point measurements of the blends prior to curing showed a strong influence of acrylonitrile on the miscibility behavior, especially near the critical composition of the system. In addition, the cloud point curves showed a highly skewed shape which turned out to be particularly favorable to the formation of a rigid but tough two‐phase structure. Blends subjected to isothermal cure at 120°C were found to begin phase separation at a progressively shorter time with increase in the copolymer content. Furthermore, while the phase domains tended to cease growing at the time of gelation, the composition within the sample continued to change well beyond the gel point.
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