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

Abstract

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/m3. Based on overall observation, this study proved that the addition of CNC on the other hand the mechanical properties showed the different result.

Biodegradation of Wasted Bioplastics in Natural and Industrial Environments: A Review

“…This leads to environmental problems due to reduction of their biodegradability [97][98][99][100]. As a replacement of synthetic fibers, environmentally friendly materials, such as lignocellulosic fibers, fillers derived from cellulosic materials [101], starch [102], can be added to biopolymers to reinforce the produced bioplastic [97,103]. Nanomaterials, such as nanoclay [104] or chitosan [102], have been used to increase the thermal stability of bioplastics developed from starch [104], which are known to have poor mechanical properties, due to their intra-and intermolecular bonds [105].…”

“…Another notable property of some bioplastics is the shape memory capability, which is a change of the shape of a material upon application of an external incentive [5]. Plasticizers, such as glycerol [86], glyoxal, or xanthan gum [108], are usually added to the starch-based bioplastics to improve their strength, flexibility [109], and the ability to process it [101]. An optimum bioplastics composition was found to be 12% (w/w) starch and 5% (w/w) glycerol [86].…”

Natural Polymeric Materials: A Solution to Plastic Pollution from the Agro-Food Sector

“…In the last 10 years, several food wastes have been used as raw material for the production of bioplastics, including biocomposites; mostly fruit and vegetable wastes rich in polysaccharides (such as cellulose, starch, pectin) and in fibers [ 90 , 93 , 101 , 103 , 104 , 105 ] ( Table A1 ). In the next paragraphs, a focus on the main uses of fruits and vegetables wastes for the production of bioplastics will be provided.…”

“…In this case, the addition of 10% of acetylated cellulose enhanced the PLA’s mechanical properties with an increase of the storage modulus at 40 °C of around 40%. More generally, cellulose or cellulose nanocrystals have been obtained from various vegetable or fruit waste, such as banana peels, pine flowers waste, rice straw, palm empty fruit bunch, sago waste, mangosteen peels, and also successfully employed as reinforcements of biopolymers, mainly starch [ 103 , 137 , 138 , 139 , 140 , 141 ]. In addition, banana pseudostems waste has been recently used to isolate nanocellulose employed for the production of green composites enriched with nano-fillers, such as graphene oxide and nanoclay, and glycerol as plasticizer [ 91 ].…”

“…In addition, not all the routes proposed for obtaining bio-materials are applicable on a large scale, since sometimes they require extensive and advanced processing. This mainly concerns biocomposites production, which is often based on obtaining fillers and reinforcements, such as cellulose nanocrystals, through complex treatment of the agro-waste [ 103 , 122 ]. On the contrary, more feasible and scalable processes allow bioplastics production after chemical extraction of agro-polymers from the food waste stream.…”