Compression induced molecular orientation and crystallization: Enhancing the thermal and mechanical properties of PMMA for aircraft interiors

Abstract

This study proposes a new approach to improving the properties of cast acrylic sheets (PMMA) through controlled post-processing compression. We significantly strengthened the material's thermal stability, mechanical performance, and morphological characteristics by applying compression below and beyond the glass transition temperature. Compression increased crystallinity by 1.32 % and reduced crystallite size by 41.81 % without altering the polymer's chemical composition. This rise in crystallinity resulted in a minor elevation of Tg for samples compressed below Tg, indicating better chain alignment. Thermogravimetric analysis (TGA) revealed enhanced thermal stability for samples compressed at 100 °C, demonstrating the potential for high-temperature applications. FESEM surface morphology revealed a brittle-to-ductile transition at 120 °C, accompanied by reduced surface roughness, as confirmed by AFM. Mechanically, compressed PMMA exhibited an 89.3 % increase in storage modulus at 120 °C, a 73.55 % rise in flexural strength, along with a 17.34 % improvement in tensile strength and a 25.86 % boost in damping capacity. These findings underscore the method's effectiveness in optimizing PMMA for aerospace and other industries demanding superior thermal stability and mechanical performance.