Development of sustainable thermal insulation based on bio-polyester filled with date pits

Date palm pit (DPP)-filled poly (-hydroxybutyrate) (PHB) composites were prepared, evaluated, and characterized to determine their thermal insulation ability. Thermal conductivity values ranged between 0.086 and 0.100 W/(m·K). At a maximum filler concentration (50% (w)), the specific heat capacity and thermal diffusivity were 1 183 J/(kg·K) and 0.068 9 mm²/s, respectively. The DPP increased the thermal stability, and the highest compressive strength obtained was 80 MPa at 30% filler content. The PHB-DPP composites exhibited promising water absorption (less than 6%) and tensile strength (6–14 MPa). Date-pit-based PHB composites could be used in sustainable building engineering and cleaner production.