thermal insulation material conductivity foam XPS Polystyrene vacuum

 https://www.researchgate.net/publication/244691560_Polystyrene_Foams_as_Core_Materials_Used_in_Vacuum_Insulation_Panel

 

 https://www.researchgate.net/figure/The-potential-of-the-thermal-building-insulation-materials-and-solutions-of-tomorrow_tbl1_320618470