Experimental Investigation of Prangos Platychlaena Boiss Fiber‐Reinforced Polyester Composites for Thermal Insulation and Construction Applications

This study explores the potential use of fibers extracted from the stems of Prangos platychlaena (PP) as reinforcement in polymer composites. Unsaturated polyester resin (UPR) was used as the matrix, and five composite groups were prepared with polymer‐to‐fiber volume ratios of 15:85, 20:80, 25:75, 30:70, and 35:65. The effects of polymer content on density, water absorption, porosity, thermal conductivity, ultrasonic pulse velocity (UPV), and compressive strength at 10% deformation were examined. Increasing polymer content raised the composite density from 0.347 to 0.759·g cm −3 and water absorption from 34.49% to 196.81%, while porosity decreased from 66.92% to 24.92%. Thermal conductivity ranged from 0.0648 to 0.0945 W·m − 1 K − 1 , indicating good potential for thermal insulation applications. Higher polymer content also improved compressive strength and UPV values. Scanning electron microscopy and energy‐dispersive X‐ray analyses confirmed that enhanced polymer content improved fiber‐matrix bonding, resulting in better element distribution on the matrix surface. Pearson correlation analysis highlighted the interrelationship among physical, mechanical, and thermal parameters. Overall, PP fiber‐reinforced UPR composites exhibited favorable thermal insulation and mechanical performance, demonstrating potential as sustainable materials for building and construction applications.