Suppressed physical aging in PMMA‐titanium oxide nanocomposites by controlling alignment of nanoparticles

Abstract

This study investigates the physical aging process of PMMA‐TiO2 nanocomposites with different particle alignments. By using an external electric field to control the alignment of TiO2 particles, a uniform distribution of TiO2 particles in PMMA is transformed into a micrometer‐level pillar structure. The physical aging process is measured using differential scanning calorimetry, and the particle alignment is confirmed by microscopy. Comparison of the aging behavior of different samples shows that the addition of randomly distributed TiO2 nanoparticles accelerates the aging rate of the material. However, when the nanoparticles are realigned into a pillar structure, the aging rate significantly decreases. Moreover, in our experimental time scale, a dual‐relaxation mechanism of aging is observed in the PMMA/TiO2 nanocomposites. This work highlights the importance of particle alignment and structure on the aging behavior of polymer nanocomposites, which could have implications for designing materials with improved stability in applications that require slow aging.