Improving the Performance and Biodegradability of Biocomposites Made from Banana Sap and Banana Fibres

Abstract

Biobased biodegradable materials are gaining popularity with increasing public awareness on the negative impacts of conventional plastics on the environment. There is, however, a lack of promising biobased materials suitable for various end-use applications that are also environmentally safe. Recently, banana sap and banana fibres have been explored as a potential source of organic material as they are abundant, cost-efficient, and environmentally friendly. In this study, two hybrid bioresins (1) banana sap maleate (BSM) and (2) banana sap maleate + banana fibre (BSMF) were developed, and their material properties and environmental suitability were examined by analysing their physicochemical characterisation and biodegradation testing. We used thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy for the physicochemical characterisation of BSMF before and after composting and measured carbon dioxide evolved during the biodegradation to calculate biodegradability. SEM analysis also showed a significant disintegration and surface degradation in BSMF compared to BSM and other control materials such as control resin and cellulose. CO2 mineralization results indicated a potential microbial bioassimilation of the materials under composting conditions. Biodegradability of the BSMF composite, as indicated by CO2 emission, was 17.6% higher than BSM and other control materials used in this study. The present study provides crucial evidence that the reinforcement of banana fibre into banana sap bioresin composite can significantly improve material properties and enhance biodegradability in the composting conditions. These results are quite promising as they show that, with some tweaking; natural materials can reduce environmental impact of composites and improve material properties for different end-use applications and involves less exploitation of nonrenewable resources for polymer production. This study also provides an avenue to consider BSMF for carrying out our future life cycle assessment (LCA) and to compare with commercial product’s LCA. In a circular economy approach, characteristics such as durability, environmental toxicity, and recyclability of such materials should be studied and optimised to reduce energy consumption and environmental impact.