Optimization of process parameters for sisal fiber-reinforced cornstarch biocomposites in sustainable packaging applications

The disposal of plastic waste is a significant eco-technological issue that addresses global environmental degradation and climate change and produces poisonous byproducts that contribute to global pollution. Ethiopia is reporting an increasing number of problems related to the growing use of plastics and their disposal, which has increased the demand for biodegradable polymers. The objective of this study was to optimize the process parameters of sisal fiber-reinforced thermoplastic starch biocomposites for sustainable packaging applications. This study examined the effects of alkaline treatment (6% wt, 12% wt, and 18% wt) and fiber content (10% wt, 20% wt, and 30% wt) on the tensile strength, water absorption, and biodegradability of biocomposites. The composite sample test was prepared according to ASTM D638 for tensile strength, which is crucial for packaging materials as it determines their ability to withstand forces during handling, storage, and transportation; ASTM D570 for water absorption, which can degrade material properties and compromise package durability; and ASTM D5338 for the biodegradability test, which is a key feature for eco-friendly packaging materials, especially in response to environmental concerns regarding plastic waste. The combination of process parameters that optimizes tensile strength, water absorption and biodegradability simultaneously was obtained using Taguchi-based grey relational analysis. The results demonstrated that a biocomposite with optimal properties was fabricated with 30% wt fiber content and 18% wt alkali treatment. The biocomposite fabricated at the optimal process parameters achieved better water absorption, biodegradability, and tensile strength values of 40.22% wt, 64.78% wt, and 4.24 MPa, respectively. These results represent the best properties for intended sustainable packaging applications.