Mechanical characteristics of composites based on oil palm empty fruit bunch, modified oca starch and polyvinyl alcohol

Abstract

Tensile behavior of empty fruit bunch (EFB) reinforced modified-starch/polyvinyl alcohol (PVA) composites was studied. Initially, oca starch was chemically modified and characterized by nitrogen content. Afterward, a modified-starch/PVA blend was prepared. Spectrophotometric assessment of blend was carried out by Fourier transform infrared spectroscopy (FTIR). Besides, blend and EFB were evaluated through thermogravimetric analysis (TGA). Composite formulation was performed considering EFB loading (10 and 20 wt. %), EFB particle size (0.425 and 0.600 mm), and processing temperature (80 and 100 °C). FTIR and nitrogen content results confirmed the presence of starch carbamates as a product of chemical modification. TGA evidenced three and four decomposition stages for EFB and blend, respectively. On the other hand, the statistical evaluation showed that EFB content and particle size-processing temperature correlation were the main influence on tensile characteristics. Overall, tensile modulus raised as EFB loading increased, whereas tensile strength decreased slightly with EFB increment. Elongation at break fell by the addition of EFB. Notwithstanding the wide dispersion of tensile properties, results showed similarities to other analogous studies. Therefore, green composites based on oca starch carbamates and EFB have the potential to be duly enhanced by the optimization of fiber-matrix interaction.