Influence of Cassava Starch Content on the Physical, Mechanical, and Structural Properties of Silica Aerogel-Containing Biofoam

Abstract

Cassava-starch-based biofoam is a promising biodegradable alternative to petroleum-based packaging materials. This study investigated the effect of cassava starch content on the physical, mechanical, and structural properties of biofoam containing corn cob fiber, polyvinyl alcohol (PVA), and silica aerogel. Four formulations were prepared by varying the cassava starch content from 48.75 to 56.25 g, while the amounts of corn cob fiber, PVA, and silica aerogel were kept constant. The samples were characterized in terms of density, water absorption, compressive strength, Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The density remained approximately 0.6 g/cm³ for samples A–C and increased to 0.7 g/cm³ for sample D. Water absorption increased from 1.3% to 3.2% with increasing cassava starch content, indicating a higher hydrophilic character. Compressive strength varied considerably, with sample A showing the highest measured value of 6.09 MPa, whereas samples B–D exhibited values of 0.10–0.15 MPa. This substantial difference suggests that compressive strength was influenced by factors beyond starch content, including pore structure, fiber distribution, matrix formation, and sample homogeneity. The anomalously high value for sample A therefore requires verification through repeated testing. FTIR analysis confirmed functional groups associated with starch, PVA, corn cob fiber, and silica aerogel, while XRD indicated both crystalline and amorphous contributions. Overall, sample A exhibited the most favorable measured properties, although further verification is required before confirming it as the optimum formulation. The developed biofoam shows potential for biodegradable packaging applications, but further characterization is necessary to establish its suitability as a direct replacement for commercial styrofoam