Declining Performance of Silicone-Based Magnetorheological Elastomers after Accelerated Weathering

Area of Science:

• Materials Science
• Polymer Science
• Engineering Materials

Background:

• Magnetorheological elastomers (MREs) are susceptible to environmental exposure, particularly sunlight and rain.
• Limited research exists on the effects of accelerated weathering on MRE properties.

Purpose of the Study:

• To investigate the chemical and rheological changes in isotropic and anisotropic MREs after accelerated weathering.
• To compare the properties of treated and untreated MRE specimens.

Main Methods:

• MRE specimens with 40% carbonyl iron particles (CIP) were prepared under varying magnetic flux densities (0 T and 1.5 T).
• Specimens underwent accelerated weathering using a Xenon Test Chamber with UV light and water spray.
• Material characterization involved Fourier-Transform Infrared Spectroscopy (FTIR), rheometry, and Thermogravimetric Analysis (TGA).

Main Results:

• Morphological analysis revealed surface roughening and increased cavities post-weathering.
• Rheometer tests showed a significant decrease in storage modulus for treated MREs (up to 85.2% reduction).
• FTIR indicated chemical structure changes, and TGA showed a slight weight decrease in weathered MREs.

Conclusions:

• Accelerated weathering causes substantial degradation in MREs, affecting their mechanical and chemical integrity.
• The findings highlight the importance of considering environmental durability for silicone-based MREs in product design.