Investigation of Structural, Mechanical, and Thermal Properties of Unsaturated Polyester Resin Based Biocomposites Reinforced with Chicken Feathers

In this study, the development of sustainable unsaturated polyester resin (UPR)-based composite materials with low thermal conductivity using waste chicken feather fibers (CFF) was aimed. To this end, by evaluating waste chicken feathers as a functional reinforcement material, the study seeks to both contribute to the recycling of environmental waste and to develop composite materials with low thermal conductivity. These composites offer significant advantages such as lightweight structure, low thermal conductivity, utilization of environmental waste, and sustainable material production. During the production process, five different mixtures were prepared with UPR/CFF ratios of 5∶95, 10∶90, 15∶85, 20∶80, and 25∶75 by volume. The produced composite specimens were comprehensively tested for their density, water absorption, porosity, ultrasonic pulse velocity (UPV), compressive strength, and thermal properties. In addition, the interfaces between UPR and CFF in the samples were examined using scanning electron microscopy (SEM). The experimental results revealed the effects of CFF content on the physical, mechanical, and thermal properties of the composites. It was observed that increasing the resin content led to higher density values, while water absorption and porosity values decreased. Thermal conductivity analysis indicated that samples with low resin content exhibited high insulation performance. Specifically, the thermal conductivity values of the samples with UPR/CFF ratios of 5∶95 and 10∶90 were below 0.1 W m−1K−1, classifying them as thermal insulation materials. UPV and compressive strength tests demonstrated that mechanical strength increased with higher UPR content; however, high CFF content negatively affected strength due to increased porosity. Through the applied experimental approach, the findings reveal that this waste material holds significant potential in terms of thermal insulation and provides a new perspective for sustainable material alternatives in the construction and insulation sectors.