Particle mobility and macroscopic magnetorheological effects for polyurethane magnetic elastomers

Area of Science:

• Materials Science
• Polymer Science
• Magnetorheology

Background:

• Polyurethane magnetic elastomers exhibit tunable properties based on their composition.
• Understanding particle mobility is crucial for optimizing the magnetorheological effect.

Purpose of the Study:

• To investigate the relationship between particle mobility and the magnetorheological effect in polyurethane magnetic elastomers.
• To determine how cross-linking density and plasticizer concentration influence magnetic particle movement and material response.

Main Methods:

• Synthesized polyurethane magnetic elastomers with varying cross-linking densities and plasticizer concentrations.
• Incorporated carbonyl iron particles into the elastomer matrix.
• Measured storage modulus at 0 mT and 500 mT, and determined the critical magnetic field.

Main Results:

• Increased cross-linking density raised the storage modulus at 0 mT and decreased it at 500 mT, while increasing the critical magnetic field.
• Increased plasticizer concentration decreased the storage modulus at 0 mT and increased it at 500 mT, while decreasing the critical magnetic field.
• The magnetorheological effect scaled with the storage modulus at 0 mT and the critical magnetic field, indicating a correlation between macroscopic elasticity and microscopic particle mobility.

Conclusions:

• Cross-linking density and plasticizer concentration significantly control particle mobility in polyurethane magnetic elastomers.
• The critical magnetic field serves as an indicator of microscopic particle mobility, directly correlating with macroscopic elastic properties.