Mechanical properties of bioplastic form cellulose nanocrystal (CNC) mangosteen peel using glycerol as plasticizer

摘要

The environmental problem due to plastic waste had become serious because it could not be recycled neither be degraded naturally by microbe in land. Thus, in the present study, a bioplastic was produced based on cassava starch as the matrix and cellulose nanocrystal (CNC) from Mangosteen peel as reinforcing filler. The CNC was added into the bioplastic with varied concentration at 1 g (BP2), 2.5 g (BP3), 5 g (BP4) and without CNC as BP1. The isolation of CNC followed series of steps (delignification, bleaching, hydrolysis and sonication) before added to the matrix. The effect of CNC addition towards mechanical properties was determined using universal testing machine (UTM) and analyzed using Fourier transform infrared (FTIR) spectroscopy. Results showed that the FTIR analysis confirmed an absorption pattern of cellulose in the starch/CNC bioplastic matrix whereas the effect in tensile strength, tensile modulus and elongation at break were compared to the pure bioplastic without CNC. The highest tensile strength peaked at 1.93 MPa while Young's modulus at 26.82 GPa was observed for BP1. On the contrary, the addition of CNC fillers to the bioplastics increased the elongation at break and the density while the elongation at break reached the lowest percentage is 13.93% and the lowest density value is 952.5 kg/m~3. Based on overall observation, this study proved that the addition of CNC on the other hand the mechanical properties showed the different result.