Development of biodegradable and low-cost electromagnetic shielding composite by waste porous biochar and poly (butylene succinate)

Pinecone is a lignocellulosic forest waste that has industrial value-added importance in energy and material production. To deepen the functional utilization of agricultural and forestry waste, exploration of materials for high-performance electromagnetic interference (EMI) shielding prevents pollution from electromagnetic radiations. Herein, low cost, environment-friendly, and efficient electromagnetic wave absorbing composites were obtained by simple and effective method using agricultural and forestry waste pinecone biochar (PB) as the carbon source and poly (butylene succinate) (PBS) as a biodegradable thermoplastic matrix. The effect of biochar content, biochar chemical and physical modification on properties of composite, especially electrical conductivity and EMI shielding performance have been investigated. Results showed that the electromagnetic shielding property of the material increased with an increase in biochar content, and the value was 54.51 dB when the pine cone charcoal content was 55%. Furthermore, these composites also showed improved thermal stability and adequate mechanical strength. Compared to untreated biochar and add coupling agents, the pickling treatment of biochar was a more effective way to enhance the EMI shielding (to 41.23%) and other properties of the composite. Furthermore, the experimental results show that it is possible to produce fully biodegradable functional polymer composites from agricultural waste.