Simultaneous enhancements in thermal insulation and toughness of resorcinol-formaldehyde/polydimethylsiloxane micro-foams

Brittleness and pulverization have troubles with phenolic porous material application in thermal insulation and mechanical elasticity. Here, we fabricated phenolic/polydimethylsiloxane composites by surface modification and sol impregnation method, it reduced the thermal conductivity and enhanced toughness. Polydimethylsiloxane (PDMS) was used as a bonding point to connect the phenolic structure, when a load was applied, the existence of wrinkles and the interface interaction effectively consumes energy so that the resorcinol-formaldehyde/PDMS materials had cyclic compressibility. Composite materials show better mechanical elasticity and thermal insulation compared to modified resorcinol formaldehyde (RF) foam. After interfacial modification and coating by different sol concentrations, the thermal conductivity significantly decreased from 0.105 to 0.75 Wm −1  K −1 . Moreover, the compression strength of PDMS/RFSi0.6 increased from 0.05 to 0.7 MPa. This work paves a simple and effective way to simultaneously enhance thermal insulation performance and mechanical properties of organic porous materials.