Heat dissipative mechanical damping properties of EPDM rubber composites including hybrid fillers of aluminium nitride and boron nitride

A Review of EPDM (Ethylene Propylene Diene Monomer) Rubber-Based Nanocomposites: Properties and Progress

Ethylene propylene diene monomer (EPDM) is a synthetic rubber widely used in industry and commerce due to its high thermal and chemical resistance. Nanotechnology has enabled the incorporation of nanomaterials into polymeric matrixes that maintain their flexibility and conformation, allowing them to achieve properties previously unattainable, such as improved tensile and chemical resistance. In this work, we summarize the influence of different nanostructures on the mechanical, thermal, and electrical properties of EPDM-based materials to keep up with current research and support future research into synthetic rubber nanocomposites.

Enhanced Thermal Conductivity of High-Density Polyethylene Composites with Hybrid Fillers of Flaky and Spherical Boron Nitride Particles

The synergistic effect between different fillers plays a crucial role in determining the performance of composites. In this work, spherical boron nitride (BN) and flaky BN are used as hybrid fillers to improve the thermal conductivity (TC) of high-density polyethylene (HDPE) composites. A series of HDPE composites were prepared by adjusting the mass ratio (1:0, 4:1, 2:1, 1:1, 1:2, 1:4, and 0:1) of spherical BN and flaky BN. The SEM results indicate that the spherical BN (with a particle size of 3 μm) effectively filled the gaps between the flaky BN (with a particle size of 30 μm), leading to the formation of more continuous heat conduction paths with the composite. Remarkably, when the mass ratio of spherical BN to flaky BN was set to 1:4 (with a total BN filling amount of 30 wt%), the TC of the composite could reach up to 1.648 Wm-1K-1, which is obviously higher than that of the composite containing a single filler, realizing the synergistic effect of the hybrid fillers. In addition, the synergistic effect of fillers also affects the thermal stability and crystallization behavior of composites. This work is of great significance for optimizing the application of hybrid BN fillers in the field of thermal management.

The Effect of Various Fillers on the Properties of Methyl Vinyl Silicone Rubber

Silicone rubber (SIR) has been widely used in electrical insulation fields, and the introduction of new materials is very important for the performance improvement of SIR composites. In this work, four different fillers, including aluminium hydroxide (ATH), yimonite (YMT), boron nitride (BN) and mica-filled SIR composites were prepared, and the vulcanization behavior, mechanical properties, insulation performance and hydrophobicity of the SIR composites were investigated and compared. Both BN- and mica-filled SIR composites showed excellent insulation performance, while the ATH-filled SIR composite exhibited the best mechanical properties with an elongation at break of 230% and a tensile strength of 2.9 MPa. The SIR/BN composite showed a breakdown strength of 29.2 kV/mm with a 5% failure rate. The addition of YMT deteriorated the insulation performance of SIR but improved the elongation at break and hydrophobicity, with an elongation at break increasing from 115% to 410% and the static contact angle improving from 109.8° to 115.6°.

Effect of the Strain Rate on Damage in Filled EPDM during Single and Cyclic Loadings

The effect of the strain rate on damage in carbon black filled Ethylene Propylene Diene Monomer rubber (EPDM)stretched during single and multiple uniaxial loading is investigated. This has been performed by analyzing the stress-strain response, the evolution of damage by Digital Image Correlation (DIC), the associated dissipative heat source by InfraRed thermography (IR), and the chains network damage by swelling. The strain rates were selected to cover the transition from quasi-static to medium strain rate conditions. In single loading conditions, the increase of the strain rate yields in a preferential damage of the filler network while the rubber network is preserved. Such damage is accompanied by a stress softening and an adiabatic heat source rise. Conversely, increasing the strain rate in cyclic loading conditions yields in a filler network accommodation and a high self-heating whose combined effect is proposed as a possible cause of the ability of filled EPDM to limit damage by reducing cavities opening during loading, and favoring cavities closing upon unloading.