Polylactic Acid/Polymethylsilsesquioxane (PLA/PMSQ) Microparticle Composites: Development and Characterization

Authors:
Preprint
Publisher website
Google Scholar
Abstract
This study presents the development of polylactide (PLA)-based biocomposites reinforced with 5, 10, and 15 wt.% polymethylsilsesquioxane (PMSQ) microparticles. The materials were prepared by melt blending followed by injection molding to evaluate the effect of PMSQ content on the morphological, thermal, mechanical, thermomechanical, rheological, and thermal conductivity properties of polylactic acid (PLA). Scanning electron microscopy (SEM) revealed a relatively uniform dispersion of PMSQ particles, especially at low filler content (up to 5 wt.%). Differential scanning calorimetry (DSC) showed that PMSQ incorporation did not significantly affect the melting temperature of PLA, while the cold crystallization temperature decreased by 14 °C combined with a higher crystallinity level. Thermogravimetric analysis (TGA) showed a slight improvement in thermal stability, with higher residual mass as PMSQ content increased. Mechanical tests showed a 7.4% reduction in Young's modulus and a 20% loss of tensile strength for the biocomposite containing 15 wt.% PMSQ due to limited interfacial stress transfer and particle agglomeration. However, dynamic mechanical analysis showed that low PMSQ concentration (5 wt.%) increased the storage modulus by 15% at 35 °C and slightly increased the glass transition temperature by up to 2 °C. Rheological analyses revealed higher storage modulus, loss modulus, and complex viscosity with increasing PMSQ content. Additionally, the presence of PMSQ enhanced the thermal conductivity of PLA by up to 23% at 75 °C. Overall, PLA/PMSQ biocomposites, especially at low PMSQ content, showed improved thermomechanical stability and thermal conductivity, suggesting their potential use in thermoforming applications.

This publication has 68 references indexed in Scilit: