An Investigation on the Effect of Silica Aerogel Content on Thermal and Mechanical Properties of Sisal/PLA Nano Composites

In this research work, the authors proposed to prepare sisal/poly(lactic acid) (PLA) composites with various amounts of silica aerogel (SAG) particles and studied the effect of aerogel content on the mechanical properties and thermal properties. Characterization of the composites in the presence and absence of aerogel particles were studied by Differential scanning calorimeter and Thermogravimetric analysis analysis. The dispersion trend of SAG particles and interfacial adhesion between the matrix and fibers were assessed by Scanning Electron Microscope (SEM) micrographs of the surface and fractured surface of the composites, respectively. The thermal degradation temperatures of PLA/Sisal composites were increased by compounding with SAG particle. The tensile strength, flexural strength, modulus and water sorption increased with SAG content in the range of 0 to 2 wt%. However, NaOH (5 wt%) treated sisal fiber nanocomposites imparts superior mechanical properties than those of untreated ones. The fracture surface morphologies showed that the SAG particles are uniformly dispersed in PLA matrix. The results obtained by SEM confirmed that the interfacial adhesion between SAG and PLA matrix was good. Biodegradation studies were also performed to study the effect of SAG particles on degradation rate of the composites. Results indicated that the addition of SAG particles improved the overall performance of the composites including their thermal stability and mechanical properties. This work provides us the exploratory idea of using SAG particles as additives in biodegradable composites for possible applications, such as interior parts of automobiles and marine industry etc. POLYM. COMPOS., 39:835-840, 2018. (c) 2016 Society of Plastics Engineers