Polymer Engineering and Science · 1987 · 28 citations · 10 references
Natural SciencesMaterials EngineeringMaterials ScienceMechanical Behavior Of MaterialsPolymer EngineeringPolymer MaterialsCross-linking DensityInjection MoldingPolymer BlendsPolymer CharacterizationPolymer NetworksPolymer ProcessingCrosslink Density EffectsCrosslinked Polymer NetworksDynamic Mechanical PropertiesImpact StrengthMechanical Strength Of PolymersPolymer Blend CompatibilizationPolymer CompatibilityPolyurethane Networks
Abstract The mechanical properties of polyurethane‐unsaturated polyester interpenetrating polymer networks (IPNs) that were prepared by reaction injection molding (RIM) process were measured with variations In composition, cross‐link density, and relative reaction rate. From dynamic mechanical analysis (DMA), it was found that the two component polymers had a good compatibility over the whole composition range. The tensile strengths of the blends were greater than those of the pure components and had a maximum value at 50/50 composition. The modulus of elasticity and surface hardness decreased and the impact strength increased as the polyurethane content was increased, but the changes were not high at low polyurethane content, below 50%. For higher cross‐link density, the compatibility was enhanced and the mechanical properties were improved. When the reaction rates of the components were different, some extent of phase separation was found in DMA and the properties were affected adversely.
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