MgO nanofiller reinforced biodegradable, flexible, tunable energy gap HPMC polymer composites for eco-friendly electronic applications

This study explores the development and characterization of eco-friendly Magnesium Oxide (MgO) nanofiller reinforced hydroxypropyl methylcellulose (HPMC) polymer composites for eco-friendly electronic applications. The prepared nanocomposites are biodegradable and flexible without any additional plasticizer. MgO nanoparticles were synthesized using the solution combustion method and incorporated into HPMC matrix through solution casting method. The structural, mechanical, optical, AC and DC electrical, and degradation properties of the prepared nanocomposites were systematically investigated. X-ray diffraction (XRD) confirmed the successful integration of MgO nanoparticles into the HPMC matrix, with noticeable interactions affecting the crystallinity. Mechanical testing revealed an optimal MgO concentration of 0.2 g, which provided the best balance of strength and ductility, while higher concentrations led to increased brittleness. UV–Vis spectroscopy results evident that the energy gap of nanocomposites can be tuneable with MgO incorporation. The photoresponsivity study indicated that higher MgO content reduce the photocurrent due to agglomeration and defect states. Dielectric studies showed a typical frequency-dependent behaviour, with enhanced dielectric constants at lower frequencies attributed to interfacial polarization. However, increasing MgO content decreased the dielectric constant and loss due to reduced polymer chain mobility and increased resistive pathways. Current-Voltage (I-V) characteristics demonstrated a non-ohmic conduction behaviour with Poole-Frenkel emission identified as the predominant conduction mechanism. Degradation tests in both tap water and soil, demonstrated that the MgO incorporation significantly slowed the degradation rate of the composites, enhancing their durability. These findings suggest that MgO-HPMC nanocomposites hold promise for sustainable and flexible eco-friendly electronic applications.