Graphene-polymer composite for thin-film heating devices

This study examines thin-film heating devices fabricated from polydiphenylenephthalide (PDPh)-based composites, a thermally and chemically stable polymer, incorporating technical graphene grades RG-S1 and RG-P1. The electrophysical and thermal properties of the composite films were characterized through I-V measurements and real-time infrared thermography. The results demonstrate that both materials provide uniform heating with a temperature variation of no more than 10 °C at low power consumption (0.10 and 0.15 mW/cm 2 to reach 70 °C). The composite with RG-P1 graphene exhibits higher electrical conductivity and heating efficiency but is prone to crack formation under cyclic loading. In contrast, the composite based on fine-dispersed RG-S1 graphene shows enhanced mechanical stability, maintaining structural integrity after multiple thermal cycles. The findings indicate the promising potential of the PDPh/RG-S1 composite for use in flexible, energy-efficient heating devices resistant to long-term operation. • New polydiphenylenephthalide/technical graphene composite for thin heaters • Efficient heating (0.10–0.15 mW/cm 2 ) at 70 °C with uniform distribution • RG-S1 composite retains flexibility after thermal cycles • Solution-processable for scalable wearable/IoT device integration