Abstract
This study investigates the fabrication and evaluation of Delrin (polyoxymethylene, POM) composites reinforcing 5, 10, 15, and 20 wt.% chopped ramie fiber (RF). The polymer composites were fabricated via injection moulding technique. Glass transition temperature (Tg), thermal conductivity, Vicat softening temperature (VST), heat deflection temperature (HDT), melt flow index (MFI), and coefficient of linear thermal expansion (CLTE) were the various thermo-mechanical and thermal characteristics of the composites that were systematically evaluated as per the ASTM standards. The Delrin matrix's performance was drastically altered by the addition of RF. Within the formulations, the composite with 15 wt.% RF had the best combination of properties: higher VST and HDT values responsible for more dimensional stability at high temperatures, lower CLTE producing lesser thermal expansion, comparatively better thermal conductivity and more heat dissipation. Eventually, there was a moderate drop in the MFI, indicating more rigid polymer chains that restricts the flowability of the composite thereby increasing the heat withstanding capabilities. DSC analysis revealed a slight upward shift in Tg and increased crystallinity, suggesting restricted polymer chain mobility and enhanced load transfer. TGA confirmed improved thermal degradation resistance, with the 15 wt.% RF displaying the highest onset decomposition temperature and maximum residue yield. At 20 wt.% RF loadings, agglomeration effects and weaker interfacial bonding with matrix led to property deterioration. Aircraft cabin component that require dimensional stability, thermal resistance, and mechanical reliability under fluctuating flight conditions include interior panels, ducting supports, and lightweight non-structural fittings. These findings demonstrate that 15 wt.% RF reinforced Delrin composites are a suitable material for these applications.
Keywords: Delrin polymer; Ramie fiber, CLTE; Glass transition temperature; Injection moulding; Thermal stability.