Fabrication of flexible porous slide-ring polymer/carbon nanofiber composite elastomer by simultaneous freeze-casting and cross-linking reaction with dimethyl sulfoxide

To develop flexible and tough composite materials with out-of-plane aligned thermally conductive pathways, a novel freeze-casting method was developed using dimethyl sulfoxide (DMSO), carbon nanofibers (CFs), slide-ring polymers (SRs), and cross-linkers. Porous composite materials composed of SR and plasma-surface-modified CFs were obtained. Using DMSO, which has a high melting point (19 degrees C) and high polymer solubility, the SR cross linking reaction was performed during freeze-casting. The CFs were treated with plasma before composite preparation for better affinity and dispersibility to the composites. The obtained porous composites contained thermally conductive pathways in the out-of-plane direction and exhibited a low Young's modulus (0.14 MPa). The composite with a thermoplastic polyurethane (TPU) elastomer embedded into its pores exhibited a low Young's modulus (3.62 MPa), high toughness (10.0 MJ/m(3)), and high thermal conductivity in the out-of-plane direction (0.57 W/mK). The proposed freeze-casting method can be applied for the fabrication of various polymers and fillers and is promising for the development of flexible porous composite elastomers with out-of plane aligned thermally conductive pathways.

Automated summary

A novel freeze-casting method was developed to create flexible and tough composite materials with vertically aligned thermally conductive pathways, showing low Young's modulus and high thermal conductivity. This method is suitable for various polymers and fillers, promising for the development of porous composite elastomers with out-of-plane aligned thermal pathways.