[Ocean Chemical Technology Frontier] Researchers develop E-TPU composite foaming material

Thread Content

Researchers develop E-TPU composite foam materials. Recently, Hubei University for Nationalities School of Intelligent Science and Engineering, Green Manufacturing of Ultra-light Elastomer Materials* * The research team of the Key Laboratory of Ethnic Affairs Committee prepared E-TPU@Ag/PDMS composite materials through a simple spraying process. Among them, E-TPU@Ag is used as a conductive component to build a conductive network, while polydimethylsiloxane (PDMS) serves as both an adhesive and an insulating protective layer. Thanks to the isolation structure design, the composite material shows excellent comprehensive performance in the X-band (8.2–12.4GHz): electromagnetic interference shielding effectiveness (EMI SE) reaches 53.3 dB, absorption coefficient is 0.74, volume resistivity exceeds 10¹¹ Ω·cm, density is only 0.51 g/cm³, and thermal conductivity is 0.19 W·m⁻¹·K⁻¹. This research provides a new strategy for the design of multifunctional composite materials that combine high shielding effectiveness, good energy absorption capabilities, excellent electrical insulation, efficient thermal insulation, and lightweight properties. At the same time, the prepared E-TPU@Ag/PDMS composite material shows broad application prospects in the field of electromagnetic interference shielding for portable and wearable electronic devices. The researchers first placed the E-TPU particles in liquid nitrogen (-196°C) for low-temperature embrittlement treatment, and then mechanically pulverized them with a high-speed grinder. The obtained powder was sieved through a 0.6 mm standard sieve, and particles with uniform particle size were collected for later use. E-TPU powder and conductive silver paint are thoroughly mixed at a predetermined mass ratio, and then the mixture is heated in a blast drying oven at 120°C for 1 hour to promote interface bonding. After the heat treatment, the sample was naturally cooled to room temperature to promote the solidification of the silver paste and form a continuous conductive coating on the E-TPU particles. The obtained silver-coated composite particles were named E-TPU@Ag. Mix PDMS prepolymer and curing agent at a mass ratio of 10:1. After stirring thoroughly, let the mixture stand until all bubbles are completely eliminated and a uniform PDMS mixture is obtained for later use. Subsequently, a predetermined amount of pre-synthesized E-TPU@Ag powder was placed in a beaker, then an appropriate amount of the above PDMS mixture was added, and stirred thoroughly to mix evenly. The resulting slurry was cast into molds of different sizes and cured in an oven at 120°C for 2 hours. After solidification, it was demoulded and cooled to room temperature to obtain the final E-TPU@Ag/PDMS composite foam.